Results of autopsy 7 months after successful endoluminal treatment of an infrarenal abdominal aortic aneurysm.

PURPOSE: To report the results of a postmortem examination in a patient who died of unrelated causes 7 months following endoluminal treatment of an infrarenal abdominal aortic aneurysm (AAA). METHODS: As part of an FDA Phase I pilot study, a 73-year-old man underwent successful endoluminal exclusion of an infrarenal AAA using a 9-cm-long endograft (Endovascular Grafting System). Seven months later, he succumbed to complications of a spontaneous esophageal rupture. At autopsy, the aorta was dissected in situ by a vascular surgeon and pathologist before being explanted in order to examine the wound healing characteristics at the aorta-endograft interface. Particular attention was also directed to the hooks composing the attachment system at each end of the endograft. RESULTS: Macroscopic and microscopic examination revealed that the graft had completely excluded the aneurysm sac from the circulation and was incorporated into the aortic wall at the proximal neck and distal cuff. A smooth pannus of endothelial cells covered the proximal end of the endograft at the areas of contact with the aorta, while microscopic examination of the distal end of the graft revealed poorly formed, fibrinous pannus. The neointima deep to the endothelium consisted of a collagenous matrix containing myofibroblasts and histiocytes, providing evidence of healing between the endograft and aorta. Both renal arteries were clear of the proximal end of the endograft, but a previously unrecognized right lower pole renal artery with an extremely caudal origin was excluded from the aortic lumen. Each hook of the attachment system was seen protruding through the adventitia of the aorta. There was no evidence of trauma to the aortic wall or the surrounding tissues caused by these hooks. CONCLUSION: There appears to be evidence that an endoluminally placed aortic graft may be incorporated by the host aortic tissue.

Auditory evoked responses, impedance measures, and diagnostic speech audiometry in severe head injury.

Three case studies are presented to illustrate the clinical usefulness of serial electrophysiologic and behavioral audiologic assessments in describing CNS function in severe head injury. There was an association among acute auditory brain stem and middle-latency evoked response findings, computed tomography of brain abnormality and neurologic status, and rate of recovery. Auditory evoked response findings 4 days after injury were also correlated with long-term outcome of diagnostic speech audiometry.

Identification of serious hearing loss with acoustic reflex data. Clinical experience with some new guidelines.

The acoustic stapedial reflex was activated by a broad-band noise signal for 326 adult subjects. Two groups were formed on the basis of pure-tone audiometry findings. Two hundred and four subjects were normal hearers or showed, at most, a mild hearing loss with a pure-tone average (500, 1000, 2000, and 4000 Hz) of less than 35 dB HL. One hundred and twenty-two subjects showed a serious hearing sensitivity impairment with a pure-tone average of 35 dB HL or greater. These acoustic reflex data were then applied prospectively in the identification of hearing impairment. Hearing sensitivity status was accurately differentiated in over three-fourths of the population. Serious hearing loss was invariably found for subjects with acoustic reflex threshold levels equal to or greater than 110 dB SPL, whereas it was effectively ruled-out by acoustic reflex thresholds in the 60 through 80 dB SPL range. The proportion of subjects with clinically significant hearing impairment is described for intermediate acoustic reflex threshold levels. These guidelines are offered as a feasible first step in clinical differentiation of hearing sensitivity status.

Further interpretation of the threshold of octave masking (TOM) test.

The threshold of octave masking (TOM) test was administered to normal-hearing and sensorineural-impaired listeners at four test frequencies; 500, 1000, 2000 and 4000 Hz. The TOM value was found to be inversely proportional to the degree of hearing loss at the masker frequency. Results indicate that the TOM test is capable of distinguishing subjects with sensorineural involvement from those with normal hearing and of providing a measure of the degree of sensory dysfunction. Examination of the slope of octave masking dysfunction. Examination of the slope of octave masking revealed that once the influence of hearing loss is overcome at higher intensities the sensorineural ear performs essentially the same as the normal ear in a tone-on-tone masking task.