Pig specific vascular anatomy allows acute infrarenal aortic occlusion without hind limb ischemia and stepwise occlusion without clinical signs.

OBJECTIVE: In a porcine, aortic graft model we found 5 animals to develop and survive unnoticed, complete infrarenal aortic occlusion and 2 pigs with an acute occlusion but rather unspecific clinical symptoms. We investigated the pigs' vascular system to classify the anatomic capabilities to compensate for an acute abdominal aortic occlusion. DESIGN OF STUDY: Retrospective analysis of CT scans and clinical data to specify unexpected results in a case series of infrarenal occlusion in a porcine model. SETTING: Collaborative study of experimental and clinical departments. SUBJECTS: Fifteen healthy female minipigs. INTERVENTIONS: All pigs underwent an infrarenal aortic graft intervention. Anesthesia and perioperative management of the animals were preformed along the standard operating procedures of the local Department of Experimental Medicine. All animals received perioperative antibiotics, ASS, and carprofen for postoperative analgesia. Arterial pressure, heart rate, body temperature, and diuresis were monitored during surgery and therapeutic interventions. MAIN OUTCOME MEASURES: Contrast media based computed tomography (CT) with total body scans were performed at 1, 4, 10, 12 weeks after surgery. Comparable scans of cardiovascular healthy subjects (humans and pigs) and patients with a Leriche's syndrome were analyzed. RESULTS: Neither acute (within the first 12 h after surgery) nor stepwise total aortic occlusion show unmistakable clinical signs. In pigs, the epigastric artery (EGA) - which is in connection with suprarenal lumbal arteries, subclavian and external iliac artery - is highly developed associated to the high number of mammary glands of about 7 on one side. In humans, the ratio of aortic to EGA-diameter is 1 : 0.15. In minipigs we found a ratio of 1 : 0.43 which changed during aortic occlusion resulting in a ratio of 1 : 0.58. Pigs with a slowly developing occlusion demonstrated an enlargement of the ureteric artery of about 210% completing a sufficient collateral system. CONCLUSION: While in the human Leriche's syndrome months are needed to enlarge the EGAs for a partial collateral support of an infrarenal aortic occlusion the pig's EGA is a naturally sufficient collateral system capable to cover immediately for an acute infrarenal aortic occlusion. Further collateral enlargement even provides a permanent, sufficient hind limb perfusion in pigs. As the sufficient collateral system probably reduce pressure and shear rates in the infrarenal aortic segment after cross clamping, pigs might have a higher predisposition to produce early thrombosis related graft occlusions tan humans.

Audiological findings after multichannel cochlear implantation in patients with Mondini dysplasia.

Mondini dysplasia is a congenital malformation of the inner ear. To date, five individuals with this malformation have received cochlear implants at the South of England Cochlear Implant Centre. The aim of this study was to review the audiological findings of these individuals after implantation. The soundfield thresholds after implantation are in the region of 30-40 dB (A). The results of suprathreshold speech recognition tasks show substantial variability in performance but this is no greater than that obtained from implant users with no malformation. All individuals were able to detect and recognize a variety of environmental sounds that would previously have been inaudible. These findings, along with the reported improvement in quality of life, mean that Mondini dysplasia is not a contra-indication for multichannel cochlear implantation. This information will be useful to other centres when considering implantation in similar patients.

Comparison of two cochlear implant speech processors in better versus poorer performers.

The performance and subjective preferences for two different speech-processing strategies, the Speak strategy in the Cochlear Spectra 22 speech processor and the Multipeak (Mpeak) strategy in the Mini Speech Processor (MSP), are compared within two adult patient groups. Ten experienced cochlear implant (CI) users were selected for this study. One group of 5 CI users have significant open-set speech recognition, and the second group consisted of experienced CI users who have little or no open-set speech recognition on standardized tests (< 30% on sentence tests; < 10% on monosyllabic word tests). While only 4 of the 5 users in each group were available to complete this evaluation, suitable comparisons on the Speak and Mpeak strategies on test performance were possible within each patient group. The performance tests were necessarily different to suit each patient group; however, general trends of test scores and subjective evaluations of each speech processor are compared between these two groups. While the performance scores and subjective ratings consistently favored the Speak strategy in the first group of users, with good open-set speech recognition, the results within the second group were more variable. These findings have significant implications for individual patient and processor selection.

A longitudinal study of symptoms, anxiety and subjective well-being in patients with vertigo.

In a prospective longitudinal study of the relationship between symptoms and anxiety in people with vertigo, 101 patients were evaluated on two occasions separated by a 7 month interval. At Time 1 the age, gender, vertigo type, duration of illness, medication, and audiovestibular test results of patients were recorded, and they completed questionnaires assessing handicap, emotional distress, predisposition to anxiety, and symptoms indicative of vertigo and of somatic anxiety. These questionnaires were re-administered at Time 2, and patients also indicated whether their vertigo was more or less severe than at Time 1. Although vertiginous symptoms at Time 2 were generally mild and intermittent, they were associated with significant handicap. Reported symptoms of somatic anxiety and arousal at Time 1 proved to be the only longitudinal predictors of perceived change in vertigo severity over the 7 month period.

Symptoms, anxiety and handicap in dizzy patients: development of the vertigo symptom scale.

Questionnaires assessing symptoms, anxiety and handicap were completed by 127 vertiginous patients. Factor analysis identified four distinct symptom clusters which formed the basis for the construction of scales quantifying the number and frequency of symptoms of: (a) vertigo (of long and short duration); (b) autonomic sensations and anxiety arousal; and (c) somatization. Scores on the vertigo severity scale were significantly related to clinical diagnosis and had near-zero correlations with measures of anxiety. Vertigo severity, autonomic signs and depressed mood each independently contributed to variance in handicap, taking precedence over the relationship between handicap and trait and state anxiety. Our findings suggest that the familiar association between anxiety and vertigo may be mediated principally by autonomic symptomatology arising as a result of somatopsychic and psychosomatic processes.

Somatic and psychological factors contributing to handicap in people with vertigo.

Questionnaires assessing symptoms, disability and handicap, predisposition to anxiety, and current anxiety and depression were completed by 127 people attending neuro-otology clinics with a major complaint of vertigo or dysequilibrium. Definite signs of vestibular dysfunction (spontaneous or positional nystagmus, or canal paresis) were found in 56% of the sample, but the presence or absence of abnormal vestibular test results was unrelated to diagnosis, reported symptoms, handicap and psychological status. Two-thirds of employed respondents admitted to occupational difficulties, and more than one in seven had left work because of vertigo. Although the number of people in the sample with a predisposition to anxiety was not unusually high, over a third of the sample had abnormally elevated levels of current anxiety. Multiple regression analyses indicated that disability was determined mainly by physical factors (vertigo severity and duration, age and sex). Handicap was influenced by a mixture of somatic and psychological variables, including the severity of autonomic symptoms. Anxiety and depression were only indirectly related to the severity and duration of the vertigo, insofar as this contributed to handicap. The partial dissociation between these different aspects of patient well-being suggests a need for separate evaluation and differing management of problems at each level of functioning.

A non-invasive, objective test of endolymphatic hydrops.

Our previous work has shown that auditory brainstem responses (ABRs) can be used to measure the basilar membrane travelling wave velocity (TWV). Based upon the hypothesis that increased pressure in the scala media will increase the stiffness of the basilar membrane and, hence, increase the speed of the travelling wave. ABRs have been used to provide a means of objectively testing for endolymphatic hydrops. Ten normally hearing subjects and 20 Meniere's patients were tested. The data for the Meniere's group show that the TWV was within normal limits at all frequencies tested, except 5.7 kHz. At this frequency, the TWV greatly exceeded that of the normal group. A short duration (15-30 min) clinical test has been developed which involves the recording of two masked brainstem responses and the measurement of the difference in wave V latencies. Clinical verification that the technique is valid was obtained by monitoring patients undergoing glycerol dehydration. The additional hardware to enable this test to be carried out with a standard evoked response system has been constructed and three, parallel, clinical trials are in hand. Currently, this technique is being applied to longitudinal studies of Meniere's patients and to evaluating the action and efficacy of various drugs. A double-blind trial using a placebo and two different drugs is underway and preliminary results are presented here.

Verification of a new test of endolymphatic hydrops.

A new objective test of endolymphatic hydrops has been described previously. The test uses auditory brain-stem response (ABR) techniques to estimate the basilar membrane travelling wave velocity (TWV). The underlying hypothesis is that raised pressure in the scala media will lead to an increase in the stiffness of the basilar membrane and that this will give rise to a travelling wave velocity that is greater than normal. It was considered that verification of the technique could be obtained by carrying out the new test before and during a glycerol dehydration procedure. Patients who required this procedure for verification of the diagnosis or as a prognostic indicator for sacculotomy, underwent the following tests. Prior to dehydration an audiogram, the ABR TWV test and a blood sample (for plasma osmolality) were taken. The patient was then given the appropriate amount of glycerol mixed with lemon juice and laid on a bed in a test room. The audiogram and a blood sample were repeated every hour and the ABR TWV test was repeatedly carried out every twenty minutes between the other tests. Six of these procedures have been carried out. In five of them the 0.5 and 1 kHz average threshold improved by at least 10dB and in all those cases the ABR TWV test showed an abnormal pre-dehydration result which moved towards the normal value following dehydration. One patient gave ABR TWV results that were within normal limits before and during the procedure and gave an audiometric change of only 5dB.(ABSTRACT TRUNCATED AT 250 WORDS)

Gastroesophageal reflux and posterior laryngitis.

Esophageal acid exposure was assessed by 23-hour ambulatory pH monitoring and compared with a biopsy of the posterior larynx and proximal esophagus in 97 patients with hoarseness, burning pharyngeal discomfort, or globus sensation. Patient results were compared with normal acid exposure times obtained in 54 control subjects. In 24 patients there were laryngeal abnormalities but both esophageal biopsy results and acid exposure times were normal. Laryngeal disease was found in association with prolonged acid exposure time or esophagitis in only 17 of the 97 patients (17.5%) studied. Recent reports appear to have overestimated the importance of acid reflux as a cause of posterior laryngitis.

Cholesteatoma following stapedectomy.

Among the possible complications of stapedectomy for otosclerosis, cholesteatoma is extremely rare. We report a case which was secondary to implantation of keratinising squamous epithelium inadvertantly included in the fat graft taken from the ear lobe to seal the footplate.

Fine needle aspiration biopsy and the otolaryngologist.

A survey of the diagnostic value of fine needle aspiration cytology in ENT practice was carried out over a 3-year period. The 119 aspirates were taken from a variety of head and neck sites and examined by an experienced cytopathologist. Cytology was accurate in 111 (93 per cent), with two false negative aspirates (1.7 per cent) and no false positive results. There were no complications and the technique was found to be a rapid, safe and cost-effective diagnostic tool.

Toxic shock syndrome after nasal surgery.

Toxic syndrome was described as a complication of nasal surgery in 1982 (Thomas et al.) and eight cases have since been reported. To our knowledge this is the first case described outwith the United States. The diagnosis should be considered in any case of unexplained collapse following nasal surgery.

Rigid endoscopy in ENT practice. Appraisal of the diagnostic yield in a district general hospital.

A 10-year retrospective survey of 204 elective rigid oesophagoscopic examinations in the ENT unit of a District General Hospital is reported. One Hundred and Forty Five (71 per cent) were normal and there was marked preponderance of normal endoscopy in patients under 60 years old. Clinical examination was usually unhelpful but barium studies were found to complement oesophagoscopy in reaching a diagnosis. There were six complications of oesophagoscopy, two following normal examinations.

Pneumosinus dilatans.

Pneumosinus dilatans is an extremely rare condition in which facial deformity is caused by gross enlargement of apparently normal paranasal sinuses. To our knowledge, this is the first case to be reported in the English literature.