Making a global difference. Reflections on working abroad.
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Audiology↗
Biomedical subjects
T Whitehill
Publications and source records attributed to T Whitehill.
The relative contributions of carotid duplex scanning, magnetic resonance angiography, and cerebral arteriography to clinical decisionmaking: a prospective study in patients with carotid occlusive disease.
PURPOSE: Recent reports suggest that 80% to 90% of patients can safely undergo carotid endarterectomy on the basis of duplex scanning alone without cerebral angiography. Other investigators have recommended that a complementary imaging study such as magnetic resonance angiography (MRA) also be obtained. METHODS: We prospectively evaluated 103 consecutive patients with carotid occlusive disease. Eighty percent of patients were symptomatic. All 103 patients underwent duplex scanning and arteriography. Additional noninvasive tests included computed tomography, magnetic resonance imaging, and MRA in 50%, 56%, and 48% of patients, respectively. At a multispecialty conference all studies except angiograms were reviewed, and a treatment decision was made by a panel of attending vascular surgeons, neurosurgeons, and neurologists. The cerebral angiograms then were reviewed and changes made to final treatment plans were noted. RESULTS: After review of noninvasive studies, 30 of 103 of patients (29%) were believed to require arteriography because of diagnostic uncertainty of carotid occlusion in three patients, suggestion of nonatherosclerotic disease in four, suggestion of proximal disease in two, suboptimal noninvasive studies in one, and uncertainty of therapy despite good-quality noninvasive studies in 20 patients primarily with borderline stenoses and unclear symptoms. In 10 of these 30 patients (33%) management decisions were changed on the basis of angiogram results. Of the remaining 73 patients (71%) in whom the panel felt comfortable proceeding with operative or medical therapy without angiography, only one patient (1.4%) would have had management altered by results of angiography. MRA results concurred with duplex findings in 92% of studies, but did not alter management in any patient. CONCLUSIONS: In patients with good-quality duplex images, focal atherosclerotic bifurcation disease, and clear clinical presentation, treatment decisions can be made without arteriography. In 30% of patients angiography is useful in clarifying decisionmaking. MRA is unlikely to influence management decisions and is thus rarely indicated.
Aged↗
Electropalatographic and perceptual analysis of the speech of Cantonese children with cleft palate.
This study used electropalatographic and perceptual analysis to investigate the speech of two Cantonese children with repaired cleft palate. Some features of their speech, as identified from the perceptual analysis, have been previously reported as being typical of children with cleft palate. For example, fricatives and affricates were vulnerable to disruption, and obstruent sounds were judged by listeners to have posterior placement. However, some apparently language-specific characteristics were identified in the Cantonese-speaking children. First there was a relatively high incidence of initial consonant deletion, and for one subject /s/ and /f/ targets were produced as bilabial fricatives. EPG error patterns for target lingual obstruents were largely similar to those reported to occur in English- and Japanese-speaking children. In particular, broader and more posterior tongue-palate contact was observed, and intrasubject variability was noted. There was also evidence of simultaneous labial/velar and alveolar/velar constriction for labial and velar targets respectively. The clinical implications of the findings are discussed.
Child↗
Aortobifemoral bypass: the operation of choice for unilateral iliac occlusion?
Aortobifemoral bypass (ABF) is the preferred operation for patients with bilateral aortoiliac occlusive disease, but for those with unilateral occlusion without significant stenosis of the contralateral iliac artery, alternative reconstructions, such as femorofemoral (FF) or iliofemoral (IF) bypass have been advocated. We compared the surgical outcome in 96 such patients after ABF (n = 32), FF (n = 47), or IF (n = 17) bypasses, with biplane arteriography and noninvasive laboratory testing used to assess the contralateral iliac artery and runoff status, in particular, patency of the superficial femoral artery (SFA). Graft patencies were assessed by noninvasive criteria and analyzed by the life-table method. The only death occurred after ABF bypass (3.1%). Primary patency rates at 1, 3, and 5 years with an open SFA were 100%, 89% and 89%, respectively, for ABF; 92%, 92%, and 92% for FF; and 71%, 71%, and 36% for IF. When the SFA was occluded, the primary patency rates at 1, 3, and 5 years were 100%, 100%, and 72%, respectively, for ABF; 72%, 53%, and 35% for FF; and 56%, 56%, and 56% for IF bypasses. There were no later occlusions on the contralateral ("good") side after ABF. Significant progression of atherosclerosis in donor iliac artery was observed in 6% of both FF and IF bypasses. We conclude that ABF is the preferred operation for extensive iliac artery occlusive disease that is hemodynamically significant only on the symptomatic side unless specifically contraindicated by prohibitive risk or abdominal disease. This is particularly true in the face of SFA occlusion.
Actuarial Analysis↗