Otolaryngology–Head and Neck Surgery

Stimulation of the cochlear nucleus (CN) has been used on a limited basis for rehabilitation of a select group of patients with bilateral acoustic neuromas. These patients were implanted with an electrode placed on the surface of the CN after resection of their tumors. Animal studies have demonstrated greater efficiency of a penetrating CN electrode in activating the central auditory system than a surface electrode. The objective of this work was to study the electrically evoked middle latency response generated by stimulation through a penetrating multichannel CN electrode in an animal model. Six pigmented guinea pigs underwent implantation with a penetrating multichannel CN electrode. Threshold, latency, and input-output functions of electrically evoked middle latency responses with different stimulation pads were studied. There were systematic differences in the latency and amplitude of the input-output functions depending on the site of stimulation within the CN. The results support the hypothesis that discrete activation of neuronal subpopulations within the CN is possible with a penetrating multichannel micro-electrode.

The Committee on Hearing and Equilibrium of the American Academy of Otolaryngology-Head and Neck Surgery recently published guidelines for reporting hearing preservation in the treatment of acoustic neuromas. These suggestions included pretreatment and posttreatment pure-tone hearing thresholds, word recognition scores, and hearing classification. We present a standardized reporting format that addresses the Committee's recommendations and displays individual patient audiologic data as a simple, concise plot of posttreatment hearing results. To illustrate the use of the recommended format, preoperative and postoperative hearing data from our institution are reported. Such reporting criteria will facilitate comparative reviews of studies of hearing preservation after surgical or radiotherapeutic management of acoustic neuromas, while providing specific data for individual patient outcome analysis.

Laryngeal electromyography has been used clinically to differentiate neuromuscular pathology from other causes of vocal fold immobility such as arytenoid dislocation, tumor invasion, or cricoarytenoid joint fixation. Electromyography has also been used to predict the prognosis for nerve recovery in laryngeal paralysis. Existing electromyographic techniques either record activity with voluntary motion or study nerve conduction. In this study a new technique, motor unit number estimation, a commercially available quantitative method of electromyographic analysis, is used to study the progress of recovery of vocal fold function after recurrent laryngeal nerve injury. Four dogs underwent transection and immediate reanastomosis of selected branches of the adductor and abductor branches of the recurrent laryngeal nerve on 1 side; the opposite side served as a control. Baseline electromyographic and videolaryngoscopic studies were performed. These measures were then repeated in a longitudinal fashion every 6 weeks after denervation. The motor unit number estimation technique indicated a return of motor unit numbers with time, along with estimates of their size. This was consistent with the expected progress of laryngeal reinnervation. These data and their predictive value for nerve recovery will be discussed.

Otolaryngologists are frequently asked to manage eustachian tube dysfunction (ETD) in patients undergoing hyperbaric oxygen therapy (HBO). HBO patients with intractable ETD currently are treated by tympanostomy tube placement; typically, these tubes are indwelling far longer than is required by the duration of HBO. Also, tubes in this population are associated with higher complication rates of persistent perforation and otorrhea. We investigated the use of thermal myringotomy as an alternative to tympanostomy tube placement in this clinical setting. Potentially, thermal myringotomy avoids the risks and complications associated with indwelling tympanostomy tubes and would be a temporally more appropriate treatment during short-and intermediate-term HBO. In this study 13 patients undergoing HBO who would have required tympanostomy tube placement instead underwent bilateral thermal myringotomies. At the fifth postoperative week, 96% of myringotomies were patent; this duration is adequate for most HBO courses. No patient required a second myringotomy for premature closure. The persistent perforation rate was 15% (at the end of 6 months), which compares favorably with the rate observed with tympanostomy tubes in this unique population of poor wound healers. Only 1 patient had otorrhea; this resolved with dry ear precautions. This study demonstrates thermal myringotomy to be an effective technique for middle ear ventilation in patients undergoing HBO in whom ETD develops.

Maxillary defects lead to functional and cosmetic deficiencies, especially with tumor invasion of the orbit and cribriform plate. Additionally problematic is the near-total palatal resection in patients with poor dentition (ie, not useful for anchoring obturators) and the desire for return of deglutition and useful speech. A series of 12 patients is presented in whom a rectus abdominis free flap was used for reconstruction of the palate, maxilla, and/or orbit. Nine of 12 free flaps were used to reconstruct defects involving the maxilla and orbit; all were successful in restoring hard palate continuity and function without the use of an obturator. The remaining 3 patients underwent successful repair of defects involving the orbit and medial maxilla without complication. Four of those 9 patients with palatal reconstruction augmented their dental rehabilitation with either their existing upper denture plate or the use of a cosmetic appliance anchored to their remaining dentition. Objectively, the rectus abdominis myocutaneous free flap proved to be a reliable and expeditious method of restoring function and acceptable cosmesis. We believe this technique should be routinely considered in the reconstruction of these defects.

Permanent facial nerve dysfunction is a potential complication of every parotid surgery. Partial superficial parotidectomy, a conservative resectioning that requires neither dissection of the full facial nerve nor excision of the superficial lobe, produces lower rates of facial nerve dysfunction and soft tissue deformity than the traditional method. This report describes a single surgeon's experience with partial superficial parotidectomy from 1987 to 1997. Fifty-nine patients with mobile, benign, and low-grade malignant tumors, limited to the superficial lobe, underwent partial superficial parotidectomy with selective nerve dissection. Adequate margins were obtained, based on the premise that the tumor-to-nerve margin is often the true one. No patients had permanent nerve paralysis or paresis, and only 10 incurred transient facial nerve paresis. Age, histology, and sex were not significant factors in postoperative facial nerve function. No patients had recurrences.

The Resident Education Committee of the Society of University Otolaryngologists constructed a questionnaire for young academic otolaryngologist-head and neck surgeons to better understand their training background and to garner their opinions concerning adequacy or deficiencies in various aspects of that training. The questionnaire was mailed to 145 individuals who were in academic posts for 5 years or fewer in 1997. There was an overall response rate of 88.3%. Of the 128 respondents, 89% identified additional training, most commonly a clinical fellowship, in preparation for an academic career. The median number of hours per week devoted to professionally related activity was 61, of which two thirds was spent in direct patient care. The most common source of funds to pursue research activities was intradepartmental resources. Most individuals were satisfied with their jobs, although one quarter were considering leaving academic practice within the year. The single most important reason motivating selection of an academic career was a desire to teach. Details of the specific training and competencies and recommendations for improvement in resident training were obtained. Specific recommendations were generated for improving the training of future academic otolaryngologists; these recommendations include clarity of job description, a single track for clinical training for academicians and nonacademicians, more training in pertinent skills including research training, protected time for research, and amelioration of some of the downsides of academic life.

To determine whether IgE in the middle ear represents a passive transudate from the serum or may be produced within the middle ear itself, paired effusion and serum from 18 atopic children with otitis media with effusion were tested by micro-ELISA for specific IgE to 12 allergens. Elevated effusion concentrations of specific IgE were present in 83.3% (15 of 18) of atopic patients, but only 30% (64 of 214) of the serum antibodies appeared in the effusion. The data show that in atopic children with otitis media with effusion, there is no relation between a patient's serum and effusion level of IgE for specific antibodies (P < 0.001), suggesting that IgE in middle ear effusion is not a transudate but more likely reflects an active localized process in atopic patients.

Microvascular reconstruction currently offers the best chance of survival for an ear segment reimplanted after amputation. Unfortunately, this technique is possible only when ear and scalp vessels remain intact. Direct reattachment of the amputated segment as a composite graft is less reliable because survival is poor for grafts larger than 2 cm in diameter. However, if survival could be improved, direct reattachment would be an attractive alternative in situations in which microsurgical revascularization is not possible. Certain pharmacologic agents have been shown to enhance the survival of composite grafts. This study demonstrated that hyperbaric oxygen, dimethylthiourea, and melatonin significantly affected the survival of reimplanted auricular composite grafts at day 7. However, by day 21 the average percentage of survival for all groups approached 13% to 14%. Dimethylthiourea had the most beneficial effect on survival early in the postoperative period, whereas the hyperbaric oxygen group demonstrated the poorest survival.

Sixty-three children aged 4 to 17 years were examined by tympanometry, pure-tone audiometry, transient-evoked otoacoustic emissions (TEOAEs), and otoscopy to evaluate the effects of middle ear pathologies and the associated hearing loss on TEOAEs. TEOAE measures were highly specific (93.8%) in identifying normal ears that passed both audiometric and tympanometric criteria. The sensitivity for identifying abnormal ears was also reasonable (83.3%). The effects of the middle ear abnormality were most significant, regardless of the degree of hearing loss, when the tympanogram was type B with normal volume measures, which is associated with reduced eardrum mobility and middle ear fluid. The middle ear conditions producing the greater negative pressure, which in turn led to more conductive hearing loss, also produced more TEOAE failures. The mere presence of an open ventilation tube was not a determining factor for absent TEOAEs because 60% of the open ventilation tubes had normal TEOAEs. Provided that the clinician understands the effects of middle ear pathologies on otoacoustic emissions, TEOAEs can be a great asset for diagnosis of both otologic and audiologic disorders.

Cell therapy is a widely applicable therapeutic approach using cells and cell elements, frequently from fetal or young animals, for their beneficial effects. This study evaluated the host response to and tolerance of transplanted fetal skin fibroblasts. Cultured fibroblasts from adult rabbit skin (autogenic and allogenic), 21 -day fetal rabbit skin (allogenic), and adult pig skin (xenogenic) were labeled with a fluorescent vital dye CM-Dil, injected intradermally into the dorsal skin of adult rabbits at multiple sites and then biopsied over an 8-week period. Each cell type showed a biphasic distribution curve with an early phase (0 to 28 days) and a late phase (28 to 56 days). In the early phase, cells showed a rise and fall in total cell density (reflecting an increase and then a decrease in total cell number), followed by a slow decrease in cell density with cells still detectable at 56 days. Fetal cells showed the highest survival at the end of the study. None of the groups showed clinical or histologic signs of acute inflammation or rejection. This study demonstrated that (1) transplanted fibroblasts are well tolerated by an immunologically competent host, (2) CM-Dil-labeled cells are detectable in vivo for at least 8 weeks, and (3) fetal fibroblasts have a distribution and survival profile that is distinct from that of adult fibroblasts.

RAST tests have traditionally been considered less sensitive than skin tests during investigation of atopy involving molds. This has been attributed to technical problems such as difficulty in binding the mold antigen to the carrier substrate. Ten patients with proven allergic fungal sinusitis were evaluated for sensitivity to 11 important molds by both RAST and dilutional intradermal testing. A predictable correlation between RAST and skin test scores was observed in many, but not all, cases. Most often this disparity was in the form of greater sensitivity indicated by skin testing than by RAST, sometimes differing by as many as 3 classes. The lack of concordance was not confined to testing for the fungi cultured from the sinuses, nor was it more or less pronounced in the case of dematiaceous fungi. The most likely causes for the disparity noted in this series are subtle differences in antigens used in skin test material and for RAST standards. Skin tests allow for evaluation of delayed and late-phase reactions, a measurement not possible by specific IgE testing with RAST. Delayed skin test reactions were not noted in this series of patients. An additional important finding was the sensitivity of patients with allergic fungal sinusitis to virtually every fungal antigen to which they were tested.

Angioedema is an immunologically mediated, anatomically limited, nonpitting edema that can lead to life-threatening airway obstruction. To predict the risk of airway compromise in angioedema, we retrospectively reviewed 93 episodes in 80 patients from 1985 to 1995. Intubation or tracheotomy was necessary in 9 (9.7%) cases. Angiotensin-converting enzyme inhibitor use in 36 cases (39%) was associated with intensive care unit (ICU) admission (P = 0.05). ICU stay correlated significantly with presentation with voice change, hoarseness, dyspnea, and rash (P < 0.05). Voice change, hoarseness, dyspnea, and stridor were present in patients requiring airway intervention (P < 0.05). On the basis of our data, we propose a staging system by which airway risk may be predicted from the anatomic site of presentation. Patients with facial rash, facial edema, lip edema (stage I), and soft palate edema (stage II) were treated as outpatients and on the hospital ward. Patients with lingual edema (stage III) usually required ICU admission. All patients with laryngeal edema (stage IV) were admitted to the ICU. Airway intervention was necessary in 7% of stage III patients and in 24% of stage IV cases. No deaths were caused by angioedema. Airway risk in angioedema may be predicted by anatomic site of presentation, allowing appropriate triage with preparation for airway intervention in selected cases.

The advantages of rigid fixation in adult craniofacial surgery are well documented, and implanted hardware is not routinely removed unless specifically indicated. There is a tendency, however, to remove hardware in children because of concerns with growth restriction, plate migration, and the lack of information on the fate of miniplates when used in pediatric craniofacial surgery. It has been our practice during the past decade not to remove hardware in children unless specifically indicated. Our study included a total of 121 procedures in 96 children, with an average age of 3.9 years and an average follow-up of 5 years. We placed 375 titanium plates and 1944 screws from 3 manufacturers. Complications encountered in children with titanium plates were as follows: 5 cases of delayed growth and 1 instance of restricted growth, 4 screw migrations (none intracranial), 9 palpable plates causing pain, 3 fluid accumulations over plates, 2 cases of meningitis, and 8 instances of plate and screw removal from the above complications. Twenty-two of 96 patients (23%) had a total of 27 complications from 121 procedures (22%). There were 6 cases in which pain precipitated removal of hardware, 1 case of an excessively mobile plate, and 1 case of documented growth restriction requiring removal; therefore our overall reoperation rate for plate removal was 8%, with no intracranial plate or screw migration.

Numerous observers have suggested a relationship between allergy and Meniere's disease, but objective proof has heretofore been limited. Using standard criteria, we studied a group of 7 patients with previously diagnosed Meniere's disease in whom significant allergy to 1 or more inhalants had also been diagnosed. Patients underwent a baseline electrocochleographic study followed by intranasal challenge with a carefully quantified amount of the allergen to which they were most sensitive. This was followed by a second electrocochleogram. Four of the 7 patients demonstrated at least a 15% increase in the summating potential/action potential ratio in 1 ear, associated with the production of subjective inner ear symptoms. We present this protocol as a potentially useful tool to further study whether inhalant allergy may be a causative factor in patients with Meniere's disease.

In this article we present a method for the objective assessment and monitoring of tissue blood supply using a specially developed endoscopic imaging colorimeter that enables quantitative color modeling of the back-scattered light during endoscopic examination. Tissue blood volume changes in the nasal mucosa, induced by xylometazoline hydro-chloride nasal spray, were evaluated with this method. It was found that quantitative imaging provides sensitive, reproducible, and reliable means for the monitoring and mapping of tissue blood supply and is easy to use routinely. The results showed that saturation decreases with time, being the most sensitive color parameter to the vasocon-striction procedure. It appears that objective indexes for optical tissue characterization and analysis may be promising in the understanding of the pathophysiology of tissue changes and in the objective evaluation of their response to different therapeutic schemes.

With increasing refinement in the surgery of vestibular schwannoma the aims of complete tumor removal and facial nerve preservation have been largely fulfilled. However, the reputation of and place for hearing-preservation surgery still remain uncertain. A major part of this uncertainty is the result of difficulties in interpretation of the various reported results of hearing-preservation surgery. Meaningful comparison between series is difficult because of the varied number of postoperative reporting criteria commonly in use today. Although it is acknowledged that the postoperative reporting criteria affect the hearing-preservation rates, what is not readily appreciated is that preoperative selection criteria for hearing-preservation cases can also significantly affect the success rate of hearing-preservation acoustic neuroma surgery. This article models the many possible outcomes of hearing-preservation schwannoma surgery by use of the previously reported Cambridge series as an illustrative example. With these models some understanding can be gained of the effect of choosing various preoperative and postoperative hearing criteria on the overall hearing-preservation success rate.

To establish the relationship between the presence of human papillomavirus (HPV) gene sequences and the development of genetic abnormalities, 31 squamous cell carcinomas of the head and neck were studied for the presence of HPV types 6b and 16 and the DNA content by flow cytometry. Eighteen (58%) cases were aneuploid. HPV DNA was present in seven (22.5%) tumors. Five of them were positive for the HPV type 6b and two for the HPV type 16. Aneuploidy was correlated with poorly differentiated tumors. No correlation was found between the presence of HPV, DNA content, or tumor differentiation. Consequently, the presence of HPV gene sequences does not seem to be related to a higher incidence of genetic abnormalities in squamous cell carcinomas of the head and neck.

The clinical course of 49 patients with the diagnosis of non-Hodgkin's lymphoma were studied in the Department of Otolaryngology of the Hospital General de Mexico between December 1986 and March 1997. The most frequent clinical symptoms in these patients were: nasal obstruction, rhinorrhea, fever, weight loss, cervical lymph adenopathy, rhinopharyngeal tumor, ulceration on the palate and periorbital cellulitis. In 73% of the patients in this series the primary presentation was nasal. Sixty-six percent of the patients were classified as intermediate grade lymphoma according to the New Working Formulation, and 33% were in a I B state according to the Ann Arbor predominant immunotype was B cell in 63% of the cases. An extensive review of the literature is also presented.