Biomedical subjects
M I Aldoori
Publications and source records attributed to M I Aldoori.
Epidural abscess formation as a complication of femoropopliteal bypass graft infection.
Explore the source record for details and available documents.
Popliteal aneurysm: the need for vigilance.
Explore the source record for details and available documents.
Smoking and stroke: a causative role. Heavy smokers with hypertension benefit most from stopping.
Explore the source record for details and available documents.
Vascular resistance in primary open angle glaucoma.
PURPOSE: To explore any difference in vascular resistance between normal and glaucoma subjects using a continuous wave Doppler technique. METHOD: The Resistance Index, RI, was calculated in two orbital vessels of 20 glaucoma patients all of whom had pressures over 23 mmHg and 15 age matched normal subjects. The haemodynamic relationship between the supratrochlear and a vessel at the optic disc, presumed central retinal artery, is expressed as RIST/RICRA. RESULTS: In 30 normal eyes the ratio was >1 m, in 10 glaucoma patients it was >1. In those glaucoma eyes which were <1, 14 improved after treatment to >1. The remaining 16 eyes which showed no change in the ratio were the eyes with moderate to severe field loss. CONCLUSION: An altered, increased, peripheral vascular resistance with reduced diastolic flow in small orbital vessels has been demonstrated in glaucoma subjects. This was not altered by treatment in the more severely affected eyes.
Carotid endarterectomy. Efficacy is proved.
Explore the source record for details and available documents.
Immunoproliferative small intestinal disease: Mediterranean lymphoma and alpha heavy chain disease.
Gastrointestinal lymphoma, uncommon in the West, is far more prevalent in developing countries where it falls into two groups: 'Western'-type lymphomas, similar to those seen in developed countries, and the so-called Mediterranean-type lymphoma. It is now accepted that Mediterranean lymphoma represents, in the majority if not in all cases, the late stage of alpha heavy chain disease (alpha-HCD). This disease is characterized by abnormal secretion of an immunoglobulin fragment; alpha-HCD and Mediterranean lymphoma constitute two ends of a spectrum of pathology now classified as immunoproliferative small intestinal disease (IPSID). IPSID is associated predominantly with poor socioeconomic conditions; patients present with progressive malabsorption in the second and third decades of life. Diagnosis is established by small bowel biopsy, with or without high serum levels of the alpha heavy chain protein. Treatment consists of an initial staging laparotomy, with debulking of lymphomatous deposits if appropriate, followed by chemotherapy or radiotherapy. Overall prognosis is poor but the recent use of doxorubicin-based chemotherapy offers some hope for the future.
Reproducibility of Doppler ultrasound measurement of resistance index in renal allografts.
In recent years measurements of arterial blood flow in the renal allograft have been studied in an attempt to provide a non-invasive method of diagnosing and monitoring post-transplant renal dysfunction. Many studies have involved measurement of the resistance index (RI) of arterial blood flow. Although the reproducibility of the technique has been studied in other areas of application, no such studies have been performed on the renal allograft. In this study we attempted to evaluate the reproducibility of the measurement of the RI of the interlobar artery in the renal allograft. 18 renal allograft recipients with stable functioning grafts were studied twice by each of two experienced sonographers using a colour-coded duplex Doppler ultrasound scanner, in order to determine the intraobserver and interobserver variability in the measurement of RI of the interlobar arteries in the allograft. Variability was small and although interobserver variability exceeded intraobserver variability, both were within repeatability limits adopted by the British Standards Institution. The results suggest that measurement of the RI of the interlobar artery of renal allografts is repeatable and reproducible when performed by experienced operators.
Monitoring renal allograft rejection with duplex sonography.
Thirty-six renal allograft recipients were monitored by serial duplex Doppler ultrasound studies post-transplant and during early rejection. A separate reproducibility study demonstrated no significant inter- or intra-operator variability in measurements of resistive index of an interlobar artery (RI) (2.1% [1.5%] and 3.2% [2.3%] respectively, mean [standard error] of coefficients of variance). Twenty-one patients had rejection within 3 weeks of transplantation. These grafts showed greater overall rises in the RI, from day 2 to day 5 post-transplant, than the grafts which had no rejection. Eleven of the 21 patients required more than one course of methyl-prednisolone for persistent or recurring rejection. These grafts had higher RI on the day rejection was diagnosed (81 [7.3], median [interquartile range]) compared with the remaining 10 patients (68.6 [8.7]). The 11 grafts with persistent rejection had higher RI (p less than 0.005, Mann-Whitney U-test) on day 2 post-transplant (76 [3.9]) compared with the 10 grafts successfully treated with a single course of methyl-prednisolone (63.2 [10.9]). This study demonstrates that grafts with an RI of greater than 70 on day 2 post-transplant are likely to have rejection requiring additional treatment (sensitivity--100%, specificity--80%). These patients may be candidates for earlier or alternative anti-rejection therapy.
Symptomatic carotid ischaemic events.
Explore the source record for details and available documents.
Proposed new classification of postendarterectomy carotid duplex scans.
Explore the source record for details and available documents.
Asymptomatic carotid murmur: ultrasonic factors influencing outcome.
Sixty consecutive patients with an asymptomatic mid-cervical murmur on auscultation were identified amongst 1000 patients who underwent duplex scanning of the extracranial carotid arteries during 1981-83. They were classified according to the scan results into 12 high risk subjects with greater than 75 per cent stenosis of an internal carotid artery, 37 low risk subjects with a less than 75 per cent stenosis and 6 with no detectable stenosis. The mean duration of follow-up was 3 years (minimum 2 years) or until stroke or death. One was lost to follow-up and four were excluded having undergone carotid endarterectomy during the study. Six of twelve subjects with greater than 75 per cent stenosis suffered a stroke (five fatal and one non-fatal). There were no premonitory signs except in one patient with non-focal cerebral ischaemia for 2 months before an hemispheric stroke. There was one fatal stroke in the less than 75 per cent stenosis group and none in the control group. In all, 17 (28 per cent) patients died (myocardial infarction, 8; stroke, 6; malignant disease, 3). These results confirm that asymptomatic carotid murmurs are associated with increased mortality with most having non-severe carotid disease on duplex scanning and few strokes during follow-up. There is an important minority with tight carotid stenosis who carry a worrying risk of stroke if left untreated.
Prospective assessment of carotid endarterectomy by clinical and ultrasonic methods.
Sixty-three carotid endarterectomies in 60 patients were followed by clinical and duplex scanning at 2 weeks postoperatively and at 3-monthly intervals for 3 years (mean 18 months). Four patients died (two of stroke, two of myocardial infarction) and four survivors had recurrent ipsilateral symptoms. Two had an immediate mild hemiparesis which recovered completely within 36 h; in both, the endarterectomized arteries were patent on scanning. The other two experienced amaurosis fugax for 2-3 weeks at 2 and 24 weeks; scanning showed that the sites of both endarterectomies had become occluded. Ultrasound assessment at 2 weeks showed that 43 of 61 (70.5 per cent) endarterectomized arteries were widely patent. There were three occlusions, one stenosis of greater than 75 per cent, three stenoses of greater than 50 per cent and eleven stenoses of less than 50 per cent. At 6 months a total of five vessels were occluded, with greater than 75 per cent stenosis in three and greater than 50 per cent stenosis in eight. At latest follow-up, six of eight arteries with greater than 50 per cent stenosis shown earlier had scans which had reverted to normal. Tacking down of the distal intima was associated with higher incidence of restenosis and occlusion (P less than 0.01). Women were more predisposed to restenosis by neointimal hyperplasia (P less than 0.05). All restenosis occurred within the first 6 months postoperatively (26.2 per cent) and fell to 16.4 per cent at the end of the study.
Duplex scanning and plaque histology in cerebral ischaemia.
Twenty-seven patients undergoing carotid endarterectomy (21 M, 6 F), with a mean age of 62 years, were studied by carotid ultrasound imaging, angiography, and histological examination of endarterectomy specimens, including Perl's stain to detect haemorrhage more than a week old. Haemorrhage into a plaque was seen histologically in 21 patients (78%), compared with 19 (70%) diagnosed preoperatively as echolucent heterogeneous plaques on ultrasound imaging. The remainder were echogenic homogeneous, fibrous plaques. In only one case was the nature of the plaque diagnosed by contrast arteriography. Excised endarterectomy specimens were inspected independently of the ultrasound assessment to determine whether the site of haemorrhage communicated with the base of an atherosclerotic ulcer. Communicating haemorrhages were present in 9 of 11 with episodic symptoms and non-communicating haemorrhages in 7 of 10 patients with a single cerebrovascular event. Perl's stain showed recent haemorrhage in 7 of 11 patients with multiple symptoms, and old haemorrhage in 9 of 10 patients with a single event. These findings suggest that ultrasonically heterogeneous communicating carotid plaques are symptomatically more active than homogeneous non-communicating plaques.
Does the in situ technique for autologous vein femoropopliteal bypass offer any hemodynamic advantage?
The improved patency rates that have been claimed for in situ femoropopliteal vein bypass have been attributed to improved hemodynamics because of the natural taper of the vein and maintenance of wall compliance because of preservation of the nutrient vasa vasorum. Blood flow in 31 in situ and 21 reversed vein grafts was measured noninvasively with a duplex ultrasound scanner at a median of 6 months after operation. There was no significant difference in the resting or hyperemic flows between the two groups (p much greater than 0.1). The compliance of 15 undisturbed and 15 fully mobilized in situ vein grafts was measured noninvasively by Doppler ultrasonography immediately after operation and at 3 months. There was a significant fall in compliance in both groups (p less than 0.001) but no significant difference between them (p much greater than 0.1). We have been unable to demonstrate any significant hemodynamic advantage with the in situ technique but believe that its use is still justified because of technically easier anastomoses and an improved utilization rate. Preservation of the vasa vasorum does not maintain wall compliance and complete mobilization of the vein relieves any uneven tension and ensures that all venous tributaries are ligated, removing the risk of arteriovenous fistulas.
Increased flow in the superior mesenteric artery in dumping syndrome.
Transcutaneous Doppler ultrasound was used to measure resting and postprandial blood flow in the superior mesenteric artery (SMABF) in nine patients with dumping syndrome and in ten normal volunteers of matching age and sex. All nine patients experienced signs and symptoms of dumping during the investigation, but none of the controls did so. At rest, SMABF in the dumping patients (567 +/- 47 ml/min) (mean +/- s.e.m.) did not significantly differ from that of the normal volunteers (493 +/- 72 ml/min). Five minutes from the end of a balanced liquid meal, flow had approximately doubled in each group (1232 +/- 140 and 941 +/- 128 ml/min). Compared with controls, increased SMABF was observed in patients with dumping syndrome at 10 min (76 per cent), 15 min (66 per cent), 30 min (55 per cent) and 45 min (42 per cent) (P = 0.05-0.01). Splanchnic pooling and abnormal redistribution of blood probably contribute to the pathogenesis of the early dumping syndrome.
Correlation of clinical findings, duplex carotid artery scanning and CT scanning of the brain in 54 consecutive patients with bruits over the carotid artery bifurcation.
Fifty-four patients presenting consecutively with bruits over the carotid artery bifurcation have been studied by Duplex ultrasonography of the carotid artery and CT of the brain. The patients were divided into symptomatic (transient ischaemic attacks (TIA), non-focal neurological symptoms, minor and major strokes) and asymptomatic groups. The duplex scans were subdivided into those showing a greater than 50% stenosis of the internal carotid artery and those with a less than 50% stenosis. The CT brain scans were subdivided into those showing evidence of cerebral infarction and those without. Symptomatic patients were found to be more likely to have an area of cerebral infarction than asymptomatic ones (P = 0.0086 Fisher's Exact Test). Patients with a significant stenosis (greater than 50%) of the internal carotid artery were more likely to have an ipsilateral cerebral infarction on CT than patients with a minor stenosis (less than 50% stenosis) (P = 0.028 Fisher's Exact Test). Three patients (two with TIA's and one with non-focal neurological symptoms) were found to have unsuspected cerebral infarcts on CT of the brain. These patients could theoretically be at risk following carotid endarterectomy and revascularization if the infarct were an early one. Patients with non-focal neurological symptoms and carotid bruit were more likely to have a significant stenosis than asymptomatic patients with carotid bruit (P = 0.0069 Fisher's Exact Test). Therapy should be directed at the carotid artery lesion in these cases. Duplex scanning of the carotid artery bifurcation may be combined usefully with CT brain scanning in the non-invasive investigation of patients with symptomatic extracranial carotid artery bruits.
A simple Doppler test for haemodynamically significant carotid artery disease.
A 10 MHz directional Doppler velocimeter was used to assess carotid atherosclerosis in 41 patients with cerebro-vascular disease. There were 30 men and 11 women with a mean age of 58 years. The arterial waveform pulsatility indices of the common carotid (CC), temporal (T), supratrochlear (ST), and central retinal artery (CRA) were compared with triplanar arteriograms in detecting internal carotid artery stenosis. The results were that Doppler signal ratios were able to differentiate less than 70% from greater than 70% stenosis and complete occlusion. For the diagnosis of internal carotid stenosis the ratio ST/CC had a sensitivity of 90%, a specificity of 93.5% and an accuracy of 93%. The CRA/CC ratio showed a sensitivity of 90% specificity of 72% and accuracy of 76%, and central retinal artery signals were difficult to detect. The T/CC ratio diagnosed external carotid artery stenosis of greater than 70% with a sensitivity of 90%, a specificity of 87% and an accuracy of 96%. The ST/CC and T/CC ratios were easy to perform, and employed routinely available Doppler velocimeters.