Faculty Bibliography

Neuroepithelial suprastructures in abnormal human inner ears were studied by light microscopy, scanning electron microscopy, and x-ray diffraction. The most common abnormality was calcification, which selectively affected the gelatinous membranes (otoconial, cupular, and tectorial) and the secretory tissues (stria vascularis and utricular dark cells). The structures most frequently affected were the otoconial membranes. The minerals involved were apatite, octacalcium phosphate, and vaterite, replacing the normal layer of calcium carbonate in the form of calcite crystals. The first two of these substances were sometimes mixed with calcite. In the saccule such abnormal otoconial deposits were usually associated with a collapsed saccular wall. Formation of abnormal otoconia is characterized as primary (no pre-existing normal calcite otoconia) or secondary (formed after the destruction of normal otoconia). Such deposits probably depend upon an abnormal composition of the endolymph, especially upon an elevated concentration of phosphate ions. It is inferred that a normal endolymphatic microhomeostasis is necessary to maintain the functional state of the neuroepithelial suprastructures.

Degree of hoarseness can be evaluated by judging the extent to which noise replaces the harmonic structure in the spectrogram of a sustained vowel. However, this visual method is subjective. The present study was undertaken to develop the harmonics-to-noise (H/N) ratio as an objective and quantitative evaluation of the degree of hoarseness. The computation is conceptually straightforward; 50 consecutive pitch periods of a sustained vowel /a/ are averaged; H is the energy of the averaged waveform, while N is the mean energy of the differences between the individual periods and averaged waveform. Recordings of 42 normal voices and 41 samples with varying degrees of hoarseness were analyzed. Two experts rated the spectrogram of each voice sample, based on the amount of noise relative to that of the harmonic component. The results showed a highly significant agreement (the rank correlation coefficient = 0.849) between H/N calculations and the subjective evaluations of the spectrograms. The H/N ratio also proved useful in quantitatively assessing the results of treatment for hoarseness.

A study was undertaken to assess the applicability of transtracheal ventilation in the instance of total upper airway obstruction. The effect of transtracheal jet ventilation through a variety of inflow catheters in the dog was studied. Arterial blood gas values, intratracheal pressure and minute ventilation were compared. Deflation of the airway through an array of outflow needles was independently assessed. Hypercapnia, decreased minute ventilation, and prolonged inspiratory and expiratory durations impaired use of the smallest catheters. A dual-lumen needle, to provide exclusive respiratory access and support was then designed based on the preliminary data. Prolonged transtracheal jet ventilation with a totally obstructed upper airway was successfully conducted in a live canine subject. A review of the literature is presented.

Barium examination of the esophagus is often useful for evaluating the cause of dysphagia, a frequent condition in patients who have undergone total laryngectomy. The examination may be difficult to interpret, however, because a variety of anatomic changes may be produced by radiation, infection, fistula, recurrent tumor, or the operation itself. Radiographic and clinical information on 45 total-laryngectomy patients, whose follow-up periods ranged from six months to 17 years, were analyzed. A recurrent tumor was found in 15 patients and was evident radiographically as a mass deviating the neopharynx in 14. Benign strictures in 14 patients appeared either as a long symmetrical narrowing or as a very short, weblike narrowing. Fistulas were demonstrated in 13 patients and presaged the development of recurrent tumors in five. Cricopharyngeal muscular dysfunction accounted for dysphagia in five cases. An understanding of these patterns leads to more accurate interpretation of the postoperative barium examination of the esophagus, and the radiographic findings often indicate the correct diagnosis with a high degree of confidence