Faculty Bibliography

The objective of this study was to determine whether insertion length and number of active channels remained the same after reimplantation of a cochlear implant. A retrospective case review of 170 consecutively implanted multichannedl cochlear implants was conducted. Seventeen of these devices had to be replaced. Data were analyzed for the Nucleus cochlear implant users who were reimplanted in the same ear. For most subjects, insertion length and number of channels remained unchanged, but a few subjects experienced substantial decreases. When the whole group was considered, a small but statistically significant drop was noted for both parameters. In conclusion, although reimplantation is technically possible, the first procedure provides the optimal surgical environment

Microvascular free-tissue transfers have assumed particular importance as reconstructive techniques of choice in centers where ablative surgery for primary and recurrent malignant disease is a focus. In the context of malignant disease, issues of surveillance for recurrence are paramount. As clinical experience with the diagnostic imaging characteristics of flap reconstructions has been acquired, magnetic resonance imaging (MRI) has assumed a prominent role in the evaluation for recurrent malignant disease. This has provided an important supportive role for contemporary concepts of immediate reconstruction. The Precise-TM Microvascular Anastomotic Device (MACD) is based on the friction-fit union of implant rings composed of high-density polyethylene and surgical stainless steel. Many characteristics of the device have been described in histologic and laboratory studies. As yet uncharacterized is the effect of clinical MRI electromagnetic fields on the device, which is composed, in part, of type 316 stainless steel. The MACD is in wide use in centers where microsurgeons are experienced with the system and it is designed to facilitate the performance and reliability of microvascular anastomoses. The implications for MRI as a safe imaging modality for the acute perioperative evaluation of patients reconstructed with microvascular free flaps anastomosed with the MACD are obvious. MACD implants of varying sizes were evaluated for displacement in each of three orthogonal planes within a 1.5 Tesla magnetic field. No change in displacement was observed for any of the devices. Magnetic resonance imaging may thus be considered a safe imaging modality for the acute perioperative diagnostic imaging of free-tissue transfers that have been anastomosed with the MACD

Decreased excitatory synaptic activity during development often leads to pre- and postsynaptic atrophy, as assessed anatomically. The present study considers the effect of decreased excitatory transmission on the maturation of synaptic strength. Towards this end, cochlear nucleus neurons, which project to the ipsilateral lateral superior olive (LSO), were denervated in gerbils at postnatal day 7, before the onset of hearing. This manipulation was intended to disrupt spontaneous glutamatergic transmission in the LSO while sparing the glycinergic afferents from the medial nucleus of the trapezoid body (MNTB). Afferent-evoked synaptic activity was assessed 1-6 days after ablation in a brain slice preparation using whole-cell current- and voltage-clamp recordings. In control animals, ipsilaterally evoked excitatory postsynaptic potentials (EPSPs) were present in 91% of neurons tested, but were observed in only 60% of neurons following cochlea removal. The maximum EPSP amplitude was significantly smaller in manipulated neurons compared with controls, and this was accompanied by a higher incidence of ipsilaterally evoked inhibitory postsynaptic potentials (IPSPs). To study the efficacy of excitatory synapses in greater detail, voltage-clamp recordings were made in the presence of strychnine and AP-5 [D(O)-2-amino-5-phosphonopentanoic acid]. The minimum excitatory postsynaptic current (EPSC) amplitude, presumed to reflect the efficacy of a single glutamatergic afferent, was approximately 40% smaller in manipulated neurons. In contrast, MNTB-evoked IPSPs were similar in neurons from control and ablated animals. However, manipulated neurons often exhibited a rebound depolarization after a hyperpolarizing current pulse or an afferent-evoked IPSP. In 70% of manipulated neurons, synaptically evoked rebound depolarizations were reduced, but not eliminated, by glutamate receptor antagonists. The glycine receptor antagonist strychnine did eliminate the IPSP-associated depolarization in these neurons. Collectively, these results suggest that functional denervation of excitatory afferents decreases their synaptic efficacy as result of both cell loss as well as decreased strength of individual surviving synapses

Comorbid conditions are medical illnesses that accompany cancer. The impact of these conditions on the outcome of patients with head and neck cancer is well established. However, all of the comorbidity studies in patients with head and neck cancer reported in the literature have been performed using the Kaplan-Feinstein index (KFI), which may be too complicated for routine use. This study was performed to introduce and validate the use of the Charlson comorbidity index (CI) in patients with head and neck cancer and to compare it with the Kaplan-Feinstein comorbidity index for accuracy and ease of use. Study design was a retrospective cohort study. The study population was drawn for three academic tertiary care centers and included 88 patients 45 years of age and under who underwent curative treatment for head and neck cancer. All patients were staged by the KFI and the CI for comorbidity and divided into two groups based on the comorbidity severity staging. Group 1 included patients with advanced comorbidity (stages 2 or 3), and group 2 included those with low-level comorbidity (stages 0 or 1). Outcomes were compared based on these divisions. The KFI was successfully applied to 80% of this study population, and the CI was successfully applied in all cases (P < 0.0001). In addition, the KFI was found to be more difficult to use than the CI (P < 0.0001). However, both indices independently predicted the tumor-specific survival (P = 0.007), even after adjusting for the confounding effects of TNM stage by multivariate analysis. Overall, the CI was found to be a valid prognostic indicator in patients with head and neck cancer. In addition, because comorbidity staging by the CI independently predicted survival, was easier to use, and more readily applied, it may be better suited for use for retrospective comorbidity studies

The purpose of this study was to determine the effectiveness of specialty pads as an intervention to reduce the incidence of intraoperatively acquired pressure sores. A convenience sample (N = 361) was drawn from all inpatients who underwent cardiothoracic or major vascular surgery on the standard operating room table (group 1), the air-filled pad (group 2), or the specialty foam pad (group 3). This sample was inclusive of 100% of patients during the study period who met the criteria. The incidence of pressure sore development was seven in group 1, zero in group 2, and one in group 3. There was at statistically significant difference (p = 0.0003) between group 1 and group 2. Additionally, a statistically significant difference (p = 0.0003) was found between group 1 and group 3. The foam pad and the air-filled pad were effective interventions for reducing the risk of intraoperatively acquired pressure sores.

The surgical treatment of chronic inflammatory frontal sinus disease over the past century has varied between intranasal and external procedures. There has been constant modification of these techniques; however, a single approach that will lead to relief of symptoms, eradication of disease with preservation of function, and a minimum of deformity has not yet been attained. The functional theory of sinus disease, the evolution of endoscopic techniques, and data provided by the computed tomography scan have renewed our interest in the anatomy of the lateral nasal wall and endonasal surgery. Extensive literature exists concerning the results of ethmoid, maxillary, and sphenoid endoscopic surgery. However, detailed information is not available on the treatment of inflammatory frontal sinusitis. The author presents the results of a retrospective analysis of a series of 101 patients with inflammatory frontal sinusitis who underwent endoscopic surgery that included the frontoethmoid complex. Results for improvement of symptoms as well as endoscopic findings are presented. Relief of symptoms was significant but did not correlate with postoperative endoscopic findings in patients with hyperplastic and polypoid sinusitis. Patients with anterior ethmoid cell encroachment on the frontal sinus outflow tract had a positive correlation between improvement of symptoms and postoperative endoscopic findings. Frontal recess stenosis was associated with a poor outcome. Anatomic obstruction of the frontonasal duct is most consistent with the functional theory of sinusitis

BACKGROUND: Alveolar ridge squamous carcinomas develop in patients outside the usual constellation of risk factors. OBJECTIVE: To determine whether the use of dentures was a risk factor specific to patients with alveolar ridge carcinoma. DESIGN: Case-control method with a unique control group-a concurrent cohort of patients with head and neck cancer with primaries in the oropharynx, hypopharynx, and larynx. SETTING: Tertiary care hospital-based clinic. PATIENTS: Forty-one patients with squamous carcinomas centered on the maxillary or mandibular alveolar ridges. The control group was 175 concurrently seen patients with squamous carcinomas of the laryngopharynx for whom dental status was known. MAIN OUTCOME MEASURES: Age at diagnosis, sex, tobacco use, alcohol use, and denture use. RESULTS: Patients with alveolar ridge were more likely to be female, older, nonsmokers, and nondrinkers. The crude odds ratio of denture use in patients with alveolar ridge cancer was 2.28 (P=.03). Eliminating other confounding factors with logistic regression, the adjusted odds ratio dropped to 1.30 (P=.59). Among patients with alveolar ridge, smoking status correlated with age and gender: current smokers were on average 64.4 years old and 9 of 16 were men. Nonsmokers' average age was 79.1 years and 1 of 11 was a man. CONCLUSIONS: In this study, denture use was not an independent risk factor for alveolar ridge carcinomas. Among patients with little to no tobacco or alcohol exposure, the alveolar ridge carcinomas tended to occur in the elderly and in women

HYPOTHESIS: Cisplatin causes the generation of reactive oxygen species (ROS), which interferes with the antioxidant defense system of Corti's organ and results in damage to the hair cells. BACKGROUND: Cisplatin is a widely used chemotherapeutic agent with the dose-limiting side effect of ototoxicity. Evidence is accumulating that cisplatin interferes with the antioxidant defense system of Corti's organ. METHODS: Organotypic explants of P-3 rat organ of Corti were the in vitro model system. Presence of intact auditory hair cells and stereocilia bundle integrity was assayed by phalloidin-FITC staining. Fluorescent dye probes detected H2O2 and intracellular thiol [e.g., glutathione (GSH)]. Spectrophotometric analysis determined antioxidant enzyme levels. RESULTS: There was a rapid dose-dependent cisplatin cytotoxicity in the explants after 48 h of exposure. An accumulation of H2O2 and a reduction of GSH levels were observed within cisplatin-exposed hair cells. L-buthionine sulfoximine, an inhibitor of GSH formation, enhanced cisplatin ototoxicity, whereas N6-(2-phenylisopropyl) adenosine, an adenosine agonist, elevated antioxidant enzyme levels and ameliorated cisplatin toxicity. The following molecules protected hair cells from cisplatin-induced damage: GSH; glutathione diethyl ester (GSHe); ebselen (EBS); 4-methylthiobenzoic acid (MTBA); and D-methionine (D-MET). EBS, MTBA, and D-MET in vitro protection correlates with in vivo protection in rats. CONCLUSIONS: Organotypic culture of Corti's organ has been validated as a model for studying cisplatin toxicity and for screening otoprotective molecules. Some of the events that contribute to cisplatin's ability to damage auditory hair cells are generation of ROS (e.g., H2O2), depletion of intracellular GSH, and interference with antioxidant enzymes within the cochlea. Agents that bolster the cochlea's antioxidant system can prevent cisplatin destruction of auditory hair cells. Identified protective agents may prove to be clinically useful in limiting or completely protecting from cisplatin ototoxicity.