Near-total laryngectomy. Patient selection and technical considerations.

OBJECTIVES: To investigate the speech and swallowing outcomes of patients undergoing near-total laryngectomy and to determine those perioperative factors that are associated with success. DESIGN AND SETTING: Retrospective analysis of a case series obtained from a hospital-based academic tertiary care center. PARTICIPANTS AND INTERVENTION: Records of all patients who underwent near-total laryngectomy at this institution were reviewed. OUTCOME MEASURES: Wound healing problems, quality of speech, degree of aspiration, and need for shunt revision were recorded. RESULTS: Thirty-nine patients during a 10-year period underwent near-total laryngectomy. Good speech was obtained in 30 (76%). Severe aspiration was a complication in eight patients (21%), necessitating reversal of the shunt in four (10%). Certain technical aspects of this procedure that produce a "hooded" myomucosal shunt were crucial to proper shunt function. Severe aspiration and poor voice outcome were most likely in patients who experienced a postoperative pharyngocutaneous fistula. These fistulas tended to occur at the junction of the pharynx and the upper end of the myomucosal shunt. When this region broke down, the hooding of the shunt was disrupted and its function impaired. CONCLUSIONS: Careful patient selection is crucial to the creation of a functional myomucosal speaking shunt after near-total laryngectomy. In patients at high risk for developing a pharyngocutaneous fistula, where irreversible aspiration through the shunt is then likely, this operation should be avoided and a total laryngectomy with tracheoesophageal puncture considered instead.

Effect of otologic drill noise on ABR thresholds in a guinea pig model.

The noise generated by the otologic drill has been implicated as a cause of sensorineural hearing loss after ear surgery. However, clinical studies on this subject are contradictory and difficult to interpret. Therefore a guinea pig model was used to study whether the level of noise generated by the otologic drill can cause threshold shifts in the auditory brainstem response (ABR). The source noise was a recording obtained during a human cadaver mastoidectomy using a microphone and an accelerometer. Ten female Topeka-strain guinea pigs were exposed to the recorded drill noise for a period of 55 minutes. Exposure included both air-conducted energy from a speaker and bone-conducted energy from a bone vibrator applied directly to the skull. ABR threshold measurements were taken pre-exposure (baseline), immediately after exposure, and at weekly intervals thereafter for 3 weeks. Three control animals were subjected to the same procedure without the sound exposure. A significant threshold shift (p < 0.0001) was seen for each frequency tested (2, 4, 8, 16, 20, and 32 kHz) immediately after exposure to noise in all experimental animals. Thresholds returned to baseline within 3 weeks. We conclude that the level of noise generated by the otologic drill in mastoid surgery can cause a temporary threshold shift in this guinea pig model.

Time allocation of students in basic clinical clerkships in a traditional curriculum.

The objective of this study was to determine the amounts of time spent in various activities by medical students enrolled in basic clinical clerkships. In the fall of 1989, 80 third-year students at the University of North Carolina at Chapel Hill School of Medicine recorded their time allocations in eight categories over 24 hours for three consecutive days. After personal time, the students spent the greatest amount of time in organized educational activities (rounds, conferences, lectures), followed in decreasing order by chartwork, patient contact, examination study, ancillary activities, procedures, and directed study. The students reported an average of 5.8 hours of sleep per night. The students reported that when they were on call, they had significant increases in patient contact, chartwork, and ancillary activities. The authors suggest that third-year students may spend too much of their time in organized educational activities, and may benefit educationally from increased amounts of patient contact and decreased amounts of ancillary activities. These data provide an opportunity for clerkship and curriculum organizers to analyze the efficacy of the basic clinical clerkships.

Inner ear damage secondary to diabetes mellitus. I. Changes in adolescent SHR/N-cp rats.

The association between diabetes mellitus and hearing impairment has been debated in many previous studies. The spontaneous hypertensive/NIH-corpulent (SHR/N-cp) rat has been shown to be a unique genetic model for non-insulin-dependent diabetes mellitus. Seventeen diabetic and 17 control young male rats were divided into groups according to diet and phenotype. The rats were fed either 54% of sucrose or 54% starch diets for 3.5 months and killed at 5 months. The cochleas were fixed, decalcified, dissected, and stained for hair cell counting. A significant loss of outer hair cells was noted in the diabetic obese (SHR/N-cp) animals when compared with the control obese (LA/N-cp) animals in every group. Although no significant difference was noted between the diabetic obese (SHR/N-cp) animals receiving the starch and sugar diets, the diabetic obese (SHR/N-cp) animals were more severely affected than the nondiabetic lean (SHR/N-cp) rats.