Applications In Otolaryngology Research Articles

Current requirements for polymeric biomaterials in otolaryngology.

In recent years otolaryngology was strongly influenced by newly developed implants which are based on both, innovative biomaterials and novel implant technologies. Since the biomaterials are integrated into biological systems they have to fulfill all technical requirements and accommodate biological interactions. Technical functionality relating to implant specific mechanical properties, a sufficiently high stability in terms of physiological conditions, and good biocompatibility are the demands with regard to suitability of biomaterials. The goal in applying biomaterials for implants is to maintain biofunctionality over extended periods of time. These general demands to biomaterials are equally valid for use in otolaryngology. Different classes of materials can be utilized as biomaterials. Metals belong to the oldest biomaterials. In addition, alloys, ceramics, inorganic glasses and composites have been tested successfully. Furthermore, natural and synthetic polymers are widely used materials, which will be in the focus of the current article with regard to their properties and usage as cochlear implants, osteosynthesis implants, stents, and matrices for tissue engineering. Due to their application as permanent or temporary implants materials are differentiated into biostable and biodegradable polymers. The here identified general and up to date requirements for biomaterials and the illustrated applications in otolaryngology emphasize ongoing research efforts in this area and at the same time demonstrate the high significance of interdisciplinary cooperation between natural sciences, engineering, and medical sciences.

Motor disorders: Evidence-based review of the use of botulinum toxins

Botulinum neurotoxin (BoNT) has emerged as a major therapeutic advance in the treatment of many disorders, affecting motor and non-motor systems. It has applications in numerous medical specialties, including neurology, rehabilitation medicine, ophthalmology, otolaryngology, gastroenterology, orthopedics, dermatology, and urology. The use of BoNT for pain disorders is an emerging and active area of interest. A task force of the Technology and Therapeutics Assessment Committee of the American Academy of Neurology performed a literature search for relevant, fully published, peer-reviewed articles related to clinical use of BoNT for neurological disorders. The panel was comprised of specialists with experience in the therapeutic use of BoNT for the indications under consideration or with expertise in guideline methodology. Authors reviewed, abstracted, and classified papers based on AAN criteria (Class I–IV). This lecture summarizes the evidence supporting the use of BoNT in neurological disorders, including adult and childhood spasticity and selected movement disorders.

Da Vinci robot–assisted endocrine surgery: Novel applications in otolaryngology

Da Vinci robot–assisted endocrine surgery: Novel applications in otolaryngology

Endoscopic management of facial fractures

Endoscopic applications in otolaryngology continue to expand, most recently in the area of maxillofacial trauma. Endoscopic management of orbital blow-out, frontal sinus, zygomatic arch, and subcondylar fractures has been described. This paper reviews the current literature including new techniques, indications, and outcomes in endoscopic management of facial fractures. Very few large studies of endoscopic fracture repair exist. The current literature, however, suggests that, when compared with an open approach, smaller endoscopic incisions result in reduced patient morbidity with similar outcomes. Dedicated endoscopic instrumentation and novel surgical approaches continue to be developed. Endoscopic repair of facial fractures is a new and evolving technique that offers the potential for reduced patient morbidity and operating time, as well as quicker patient recovery. Current applications include the management of orbital blow-out, frontal sinus, zygomatic arch, and subcondylar fractures. It should be emphasized that endoscopy augments, rather than replaces, the 'time tested' principles of adequate skeletal exposure, accurate fracture reduction, and appropriate internal fixation.

Combination of propofol and tranexamic acid as a protocol of providing optimal surgical condition in comparison with halothane during tympanoplasty

Introduction: Tympanoplasty is accomplished under general anesthesia. One major drawback of general anesthesia is the increased bleeding encountered, which can interfere with optimal visualization of the microscopic surgical field. We performed a prospective study to compare the effect of combination of propofol and tranexamic acid as a protocol versus halothane on blood loss and the surgeon's subjective assessment of operating conditions during tympanoplasty. Materials and Methods: 40 patients undergoing tympanoplasty were randomly assigned to receive the mentioned protocol or halothane (n=20). One surgeon , who was blinded to the anesthetic agent, performed all the operations, and assessed surgical condition, using a grading system of score as follow: 1. minimal or no bleeding 2. modest bleeding 3. significant bleeding 4. severe bleeding. Results were compared in the two anesthetic groups using appropriate statistical tests. Results: There was no difference between the duration of surgery or the intraoperative mean arterial pressure when comparing the two groups. Mean bleeding scores were less over time with above protocol. 80% of the patients had a satisfactory visualization of the surgical field in protocol group, while it was 45% in halothane group. Conclusions: General anesthesia, based on the combination of propofol and tranexamic acid may have the advantage of decreased bleeding compared with conventional inhalation agents, making tympanoplasty technically easier and safer by improving visualization of surgical field. This anesthetic technique may have other applications in otolaryngology, when bleeding within a confined space frequently can interfere with visibility.

Da Vinci Robot-Assisted Excision of a Vallecular Cyst: A Case Report

The da Vinci Surgical System is a new and exciting entrant into the field of robotic technology. This system is undergoing considerable research and is being practically applied in general surgery, cardiothoracic surgery, urology, and gynecology. We have previously described our experience with the da Vinci system in the laboratory setting, and we have reviewed its potential applications in otolaryngology. Here we present a case report of the first da Vinci-assisted excision of a vallecular cyst in a human. Although we initially encountered some difficulties in the setup, we were able to perform the procedure with moderate ease and without complication. The potential of the da Vinci system in otolaryngology is promising. Further research is needed to explore all of its possible uses in our field.

Otolaryngology-head and neck surgery residency match: applicant survey.

To examine satisfaction with the match process and reported failures to comply with the match rules among applicants of the January 2002 Otolaryngology-Head and Neck Surgery match. A survey was mailed to all applicants completing the 2002 San Francisco Matching Program match. Surveys were mailed to 312 applicants, and the 151 returned surveys were entered into a database, which was then subjected to statistical analysis. Survey questions asked whether the applicant matched and how highly, how well the applicant considers the match to fulfill its goals, how many interviews the applicant attended, and how many of these included perceived noncompliance with San Francisco Matching Program rules by region of the country. Satisfaction with the match correlated significantly (P<.001) to how highly the applicant matched among those successfully matching. The satisfaction among matching applicants was significantly better (P<.001) than those not matching. The 151 respondents had a total of 970 interviews. The respondents reported that they identified noncompliance with the match rules in 42 (4.3%) of these encounters. Most (87%) respondents reported full adherence to the match rules, and the degree of adherence did not correlate significantly to applicants' satisfaction (P =.71). Applicants' satisfaction with the match process depended significantly on their match outcome. Rule noncompliance was rare and not significantly related to applicant satisfaction. This study suggests that otolaryngology applicants perceive high levels of satisfaction with the match and infrequent breaches of stated match rules.

Surgical robotic applications in otolaryngology.

To explore the feasibility of performing endo-robotic neck surgery in a porcine model and to compare the results of robotically enhanced endoscopic surgery with those from a conventional endoscopic technique. Prospective, nonrandomized experimental investigation in a porcine model. We performed a consecutive series of endoscopic neck surgeries using the daVinci surgical system (Intuitive Surgical Inc.). The length of time required to establish the operative pocket and to assemble the robotic components, as well as the total duration of each operation, was recorded. The animals were continuously monitored for heart rate, blood pressure, and end-tidal CO(2) pressure, and evaluation for presence of pneumothorax and subcutaneous emphysema was undertaken postoperatively. The specimens were examined histologically. Four different types of neck surgery were successfully performed on both sides of the neck of four animals using the daVinci surgical system. Creation of the operative pocket took, on average (+/-SD), 18.1 +/- 11.9 minutes, and assembly of the robot required 12.5 +/- 9.9 minutes, resulting in a mean preparation time for all procedures of 30.6 +/- 21.0 minutes. The mean operative time for submandibular resection (n = 3) was 19.0 +/- 6.6 minutes, with a total procedure time of 39.0 +/- 10.2 minutes. Selective neck dissections (n = 3) required a mean operative time of 66.0 +/- 18.5 minutes and a total procedure time of 85.7 +/- 16.7 minutes. One partial parotidectomy and one thymectomy were also performed. The median estimated blood loss was 0 mL (range, 0-10 mL). The end-tidal CO(2) pressure fell from the start to the end of the procedures by a mean of 4.4 +/- 7.9 mm Hg. The blood pressure fell by a mean of 1.9 +/- 7.5 mm Hg. There was one case of modest subcutaneous emphysema, and there were no cases of pneumothorax or air embolism. No conversions to open resection were necessary. Robotically enhanced endoscopic surgery in the neck is feasible and offers a number of compelling advantages over conventional endoscopic neck surgery. Clinical trials will be necessary to determine whether these advantages can be achieved in clinical practice.

Outpatient intravenous antibiotics for chronic rhinosinusitis.

Peripherally inserted central catheter (PICC) lines have greatly facilitated the use of intravenous antibiotics in outpatient medical practice. Otolaryngologic applications for home intravenous therapy through PICC lines have not been well characterized to date. The purpose of the study is to describe indications and complications related to outpatient intravenous antibiotic therapy in patients with chronic rhinosinusitis. Retrospective cohort study. Chart review of patients with chronic rhinosinusitis who were treated at an academic rhinology practice with outpatient intravenous antibiotics over a 3-year period. RESULTS Fourteen patients receiving, in all, 16 courses of intravenous antibiotic therapy through PICC line were identified. The average patient age was 51 years (age range, 36-74 y). The primary indication for intravenous antibiotic use was the treatment of resistant pathogens (50%). The most common organisms treated were, and. Other indications included gastrointestinal intolerance of oral antibiotics and extranasal complications of sinusitis. Eighty-eight percent of patients (14 of 16) were able to complete the entire prescribed course of therapy. Three (19%) catheter-related complications occurred, including thrombophlebitis and deep venous thrombosis. All three complications required removal of the PICC line; one of these patients underwent successful reinsertion of a second catheter and completion of treatment. Peripherally inserted central catheter line delivery of home intravenous antibiotics can be a well-tolerated adjunct to surgery in the outpatient treatment of chronic rhinosinusitis. Resistant infections, intolerance to oral antimicrobials, and extranasal complications of sinusitis are indications for PICC line therapy. Catheter-related complications can be significant and must be considered in patient selection.

Telemedicine in otolaryngology

Background: Telemedicine (TM) is the use of advanced information and communication technology to provide health care services. TM in general, and specifically in the field of otolaryngology, has become a reality. Because of the improvements in telecommunications and computer technology, TM applications are becoming more common in both hospitals and private practice. These applications are altering the manner in which otolaryngology is practiced both at the primary care and the specialist level. This study reviews and summarizes the use of TM specifically in otolaryngology, and discusses some of its advantages, barriers, and future. Material and Methods: A review of the current literature pertaining to the use of TM applications in otolaryngology—head and neck surgery was performed. Results: TM applications are being developed and used worldwide in the many fields of otolaryngology. As telecommunication and audio-visual technologies advance, these applications become more exacting and cost effective. Conclusion: We encourage the otolaryngologist to understand the technical, legal, ethical, and financial impact of TM on managed care in otolaryngology and to make use of the potential opportunities of TM in otolaryngology—head and neck surgery. (Am J Otolaryngol 2002;23:35-43. Copyright © 2002 by W.B. Saunders Company)

Fibrin glue applications in pediatric otolaryngology

Fibrin glue applications in pediatric otolaryngology

Introduction: Laser Applications in Otolaryngology

The perception of the laser has changed as lasers have moved from the laboratory into everyday conventional surgery. The physician's perception of the laser has expanded from the simple light scalpel to a tool with a variety of applications. This issue of Otolaryngologic Clinics of North America is designed to explain how lasers are used today in otolaryngology-head and neck surgery and to indicate new directions for the laser tomorrow.

Computer‐assisted surgical techniques using the vanderbilt free electron laser

The Vanderbilt Free Electron Laser (FEL) is capable of lasing between 2.0 and 8.0 microns with a high peak intensity pulsed structure. The FEL is used to investigate potential applications in otolaryngology. Charring of temporal bones and thermal stress patterns in Plexiglas indicate thermal buildup at 20 and 10 Hz repetition rates of the laser. Also, transient temperature changes measured with thermocouples in a gelatin model reveal that significant heat production occurs at these laser repetition rates. To utilize the fastest laser repetition rates and maintain minimal lateral thermal damage, a computer-controlled scanning system was devised. The authors have also used the computer control with the carbon dioxide laser and experienced improved ablation.

Propofol for maintenance of general anesthesia: A technique to limit blood loss during endoscopic sinus surgery

Purpose: Most cases of endoscopic sinus surgery are amenable to techniques using local anesthesia with monitored sedation. However, it is frequently the preference of the patient to have surgery under general anesthesia. One major drawback of general anesthesia is the increased bleeding encountered which can interfere with optimal visualization of the intranasal anatomy. In this study, an analysis was made to see if technique of general anesthesia has an impact on estimated blood loss in patients undergoing endoscopic sinus surgery. Methods: Twenty-five patients undergoing outpatient endoscopic sinus surgery under general anesthesia over a 1-year period were reviewed retrospectively to determine if anesthetic technique had an impact on estimated blood loss. Twelve patients were identified who received a continuous intravenous infusion of the nonbarbituate hypnotic agent propofol as the primary anesthetic agent, and 13 patients were identified who received anesthesia based on inhalational isoflurane. Results: There was no difference between the duration of surgery or the intraoperative mean arterial blood pressure when comparing the two groups. The average estimated blood loss in the propofol group was 101 mL compared with an average estimated blood loss of 251 mL in the isoflurane group ( P < .01). Conclusions: General anesthesia based on propofol infusion may have the advantage of decreased bleeding compared with conventional inhalation agents, making endoscopic sinus surgery technically easier and safer by improving endoscopic visualization of the surgical field. This anesthetic technique may have other applications in otolaryngology, where bleeding within a confined space frequently can interfere with visibility.

Computer recognition of brain stem auditory evoked potential wave V by a neural network.

A neural network simulator was used for the recognition of the presence and location of the peak of wave V of the brain stem auditory evoked potential (BAEP) test. Waveforms selected from BAEPs performed in the last 4 years at the University of Pittsburgh Presbyterian University Hospital were digitized and sampled, and the resulting amplitudes were normalized. A training set was composed of the waveforms resulting from the stimulation of 50 ears. The normalized amplitudes were used as the initial activation values for the networks. The desired outputs (the target locations for wave V) were represented in the output layer by setting the output element, which corresponded to the target location and its immediate neighbors, to high activation levels, and all the remaining output units to zero activity. Two network architectures, differing only in the hidden unit layer, with 40 and 16 hidden units, respectively, were trained by using standard back-propagation. Several trials from different starting points were performed for each architecture. The best network, found after 60 epochs (3,000 presentations), was able to correctly identify 17 of 20 cases (85%) from a set of test cases that were independent from the training set.

Bone ablation with Er:YAG and CO2 laser: study of thermal and acoustic effects.

A pulsed Er:YAG laser at 2.94 microns and a superpulsed CO2 laser at 10.6 microns are used to investigate bone ablation applications in otolaryngology. Quantitative measurements of mass removal and the ablation depth of cat skull bone and rat femur are presented with the Er:YAG laser at fluences of 9-117 J/cm2. Histological results show that the minimal thermal injury zone from the edge of the lesion is 5-10 microns. Comparison of the photoacoustic and thermal effects during the ablation process indicates that the temperature rise from the 10.6-microns light was higher than that from the 2.94-microns light but that the photoacoustic wave amplitude produced with the Er:YAG laser was higher than that with the CO2 laser. The fluence used for the efficient ablation of bone tissues produces a photoacoustic wave ranging from 100 to 120 dB. The ear can tolerate this level for a short time period. Results of this study suggest that the Er:YAG laser can be an important surgical tool in otolaryngology.

Physics of Light and Lasers

Because most laser procedures use the heating effect of the light and given the number of parameters that may be varied--such as power density, power, pulsing, and heating of fiber tips and probes--significant overlap in applications of the various lasers can result. This is readily apparent in the conflicting claims of laser manufacturers seen in promotional materials. Despite this, each type has its strengths. The CO2 laser is a specialty instrument, particularly for microscopic applications in neurosurgery, otolaryngology, and gynecology. Its hemostasis and vaporizing abilities allow its use in dermatology and in general surgery for tumor resection and hemostasis. In gynecology it seems best for colposcopy (cervical and vaginal) and, through a micromanipulator, for laparotomy. The beam is focused and delivered by handpieces and micromanipulators on microscopes. Through the laparoscope, it requires the use of a special laser coupler on a special laser laparoscope to allow for line-of-sight delivery of the beam through the operating channel. Waveguide delivery systems have been introduced for CO2 laser laparoscopy using standard laparoscopes. These function as hollow, slender tubes through which the beam is transmitted by means of hundreds of glancing internal reflections in the tube, which emits the beam at its tip. This eliminates many of the alignment problems of coupler cube-type systems and allows the beam to be delivered close to the target. The Nd:YAG laser is the primary endoscopic instrument in pulmonology, gastroenterology, and urology. The use of contact tips, though not a panacea, increases its applications, particularly in general surgery. Its primary use in gynecology is for endometrial ablation with bare fibers for deep coagulation. Its use for laparoscopy with contact probes or sculpted fibers is quickly growing. Green light lasers (argon and KTP) are color-selective photocoagulators and may be used to cut tissue. They are fiberoptically delivered like the Nd:YAG laser. Their best use in gynecology appears to be a versatile instruments for operative laparoscopy and the simple treatment of endometriosis. A standard quartz fiber with these lasers is usually more versatile than a contact tip with an Nd:YAG laser when used for cutting.

Use of human amniotic membrane as a biologic dressing

Human amniotic membranes have been used successfully for over 70 years for a wide range of surgical applications. This readily available, inexpensive, easily stored allograft has almost no antigenicity and has considerable antibacterial potential. Ability to reduce occurrence of exudate, adhesions, drying and scarring in surface defects are further properties of this remarkable membrane. Apart from specific otolaryngologic applications of amniotic membranes previously reported by our group, we use human amnion for overlaying epithelial defects after flap necrosis following surgery in the head and neck area, and in covering free skin graft donor regions, with good results. Properties of the human amniotic membrane are reviewed and discussed.

Comparison of the erbium‐yttrium aluminum garnet and carbon dioxide lasers for in vitro bone and cartilage ablation

The in vitro bone- and cartilage-ablation characteristics of the solid-state erbium:yttrium aluminum garnet laser were compared to those of the carbon dioxide laser. Ablations of fresh, frozen cadaver septal cartilage and maxillary sinus bone were performed using total energies between 1 and 6 J. Specimens were studied using hematoxylin and eosin stain and digitized, computer-assisted measurements of 35-mm photographs. Erbium-yttrium aluminum garnet-ablated bone averaged 5 microns of adjacent tissue thermal injury, compared with 67 microns with carbon dioxide-ablated bone. Erbium-yttrium aluminum garnet-ablated cartilage averaged 2 microns of adjacent tissue thermal injury, compared with 21 microns with the carbon dioxide-ablated cartilage. The tissue-ablation characteristics of the erbium-yttrium aluminum garnet laser are promising for future otolaryngologic applications.

Laser Application in Otolaryngology — Head and Neck Surgery

Since the discovery of the laser in 1959, a wide variety of lasers have been developed with numerous clinical applications in medicine and surgery. Lasers have had a great impact on the surgical approach to both benign and malignant diseases in Otolaryngology-Head and Neck Surgery, and have enabled the otolaryngologist to manage diseases in the aerodigestive system primarily through an endoscopic approach. We will summarize the physical properties of the currently used lasers in otolaryngology, as well as their clinical applications.