Ultrasonic doppler spectral broadening in the diagnosis of internal carotid artery stenosis.

In a clinical study, 78 carotid bifurcations were examined by pulsed Doppler ultrasonography and X-ray arteriography. Maximum Doppler frequencies greater than or equal to 3 kHz diagnosed stenoses of greater than or equal to 25% diameter reduction with a sensitivity of 73% and specificity of 79%. A quantitative analysis of the degree of spectral broadening was obtained from the ratio of the maximum to mean frequency at peak systole and improved the sensitivity and specificity to 90% and 98% respectively. All vessels greater than 40% stenosis were correctly classified as stenosed and all less than 20% stenosis were classified as normal.

Evaluation of indirect blood pressure measurement as a method of assessment of peripheral vascular disease.

In over 200 patients with peripheral vascular disease, pressure index (formula: see text) was compared with radiological grade; although calf P.I. had a better correlation, there was wide overlap between the groups. In 28 patients, resting calf P.I. was compared with functional impairment measured on a treadmill. At two rates of exercise, calf P.I. correlated poorly with functional impairment. In 35 patients, reproducibility of indirect pressure measurement was assessed; coefficients of variation ranged 0-10%; coefficient of variation of calf P.I. ranged 0-8%; coefficient of variation of calf P.I. ranged 0-8%. In 12 patients, indirect thigh systolic pressure was compared with and nearly always exceeded direct common femoral artery pressure; this was due to an effect of the cuff which reduced blood flow and reduced the pressure gradient. This methodological error has not previously been described and reduces the clinical value of the measurement.

Radiographic anatomy of the extracranial carotid artery.

Only 55% of common carotid arteries bifurcate in the neck at the classically described level of C3 vertebra or C3/4 interspace. Others bifurcate as high as C2/3 interspace or as low as C5/6. Eighty-five percent of bifurcations occur at the same height as that on the contralateral side. Even if asymmetry occurs, it is not greater in magnitude than the height of one cervical vertebra. Atheroma does not appear to be associated with any particular bifurcation position. Abnormally curved or kinked morphology of the extracranial internal carotid occurs in 6% of angiograms. This feature also has no specific association with atheroma.

Amyloid disease: association with failure of arterial reconstruction.

Amyloidosis may accompany many chronic diseases and in particular occurs as a complication of myelomatosis in 10% of cases. This paper reports the effects of amyloid in major arteries of the leg, and describes attempts to treat this occlusive disease using vascular grafts. Such disease may be rapidly progressive and its presence may indicate a poor outlook after vascular surgery. Arterial biopsy at the time of operation in patients with diseases associated with amyloidosis may be useful in assessing prognosis.

Pulsed Doppler imaging and spectrum analysis for detection of carotid artery disease.

One hundred carotid arteries in 53 patients suffering from transient cerebral ischaemia or amaurosis fugax have been studied prospectively. Internal carotid arteries were assessed by a six-channel pulsed Doppler imaging system combined with Doppler spectrum analysis and the findings compared with those obtained by X-ray contrast arteriography. Stenosis (greater than 25% diameter reduction) was correctly diagnosed by ultrasonography with a sensitivity of 93% and a specificity of 96%. Occlusion was correctly diagnosed with a sensitivity of 92% and a specificity of 97%. The ability to recognize arterial stenosis and occlusion with this noninvasive system suggests that it has a major part to play in screening patients with suspected carotid artery disease.

Pressure contour analysis in the assessment of arterial stenosis.

Femoral artery pressure contour can be measured directly by percutaneous needle puncture and may be a useful indicator of proximal vessel stenosis. Pressure waveform in 53 limbs was compared with radiological appearance of the aorto-iliac segment. Forty-one limbs were graded angiographically as normal and 12 as stenosed. Pressure contour was studied at rest and after intra-arterial injection of papaverine. The following parameters were examined: 1. systolic pressure at rest 2. systolic pressure after papaverine 3. per cent reduction of systolic pressure after papaverine 4. pulse pressure at rest 5. pulse pressure after papaverine 6. per cent reduction in pulse pressure after papaverine 7. maximal gradient (dp/dt) at rest 8. maximal gradient after papaverine: p less than 0.001 (Figure 5b) 9. (formula; see text) A significant difference between the angiographic normal and stenotic groups was found in the values of all parameters. p less than 0.001 for 1 to 8 inclusive; p less than 0.05 for 9. Good discrimination between groups was achieved only by 3, 6 and 8. Three produced the best discrimination: systolic pressure reduction after papaverine greater than or equal to 14 per cent indicating stenosis (1 in 12 false negative) and less than 14 per cent indicating no stenosis (no false positive).

Pulsed Doppler imaging for carotid artery disease.

Ultrasonic imaging using a six-channel pulsed Doppler system combined with Doppler spectral analysis of 65 carotid bifurcations has been studied in a prospective clinical trial. The results were compared with X-ray contrast angiography. An overall sensitivity in excess of 90 per cent was achieved using the ultrasound technique, with a specificity of 89 per cent in the detection of significant stenosis or occlusion of the internal carotid artery. The ability to recognise significant arterial stenosis with a non-invasive system suggests that it has a major part to play in screening patients with suspected carotid artery disease.

Phenol sympathectomy in the treatment of intermittent claudication: a controlled clinical trail.

Twenty-five patients with intermittent claudication were randomly allocated to treatment either by injection of phenol into the lumbar sympathetic chain or by injection of local anaesthetic subcutaneously. On the day after the injection, sympathectomy, assessed by skin temperature change, was achieved in 85 per cent of the phenol group. At 1 month subjective improvement was claimed by 45 per cent of the patients in the sympathectomized group and by 64 per cent in the control group; at 3 months the figures were 25 and 45 per cent respectively. Treadmill testing at two exercise loads showed no significant difference in claudication distance or stopping time between the two groups. Calf blood pressure response following exercise was not affected by sympathectomy. There is no subjective or objective evidence that phenol sympathectomy improves intermittent claudication.

Carotid artery bruit: association with internal carotid stenosis and intraluminal turbulence.

One hundred and ninety-five consecutive referrals to the vascular laboratory for carotid artery investigation have been studied. Carotid bruits were assessed by the referring clinician and documented. All patients underwent bilateral imaging and spectrum analysis of the extra-cranial carotid vessels using a pulsed Doppler ultrasound technique. Eighty-two were further assessed by X-ray contrast angiography. Of 390 internal carotids examined by ultrasound, 65 exhibited intraluminal turbulence of which 49 (75 per cent) had a bruit. In 62 (56 per cent) of 111 internal carotids in the series which were said to have a bruit on clinical examination, no turbulence was found; in 15 instances the external carotid vessel was shown as the true source of turbulence and in the remainder the bruits may have been transmitted from the heart. One hundred and fifty-six vessels were assessed by X-ray and 55 shown to have significant stenosis; 38 (69 per cent) of these exhibited a bruit. Bruit was often absent at high degrees of stenosis and in occluded vessels. Although a carotid bruit is often a marker of internal carotid intraluminal turbulence and stenosis, this is by no means always so. Cervical bruit may also be due to a diseased external carotid or to sounds transmitted from a more proximal source. Conversely, absence of bruit is a feature not only of normal vessels but of many arteries which are stenosed (especially if this is of high degree) or occluded.

The significance of blood pressure measurements in patients with peripheral vascular disease.

The pressure drop across a stenosis is related only to its geometry and the flow through it. Flow may be manipulated by changing peripheral resistance, enabling information to be gained about the severity of the stenosis. As changes in blood flow may produce changes in local blood pressure in patients with peripheral arterial disease, measurements of blood pressure should be made at flow conditions appropriate to the symptoms under investigation, or should be performed by methods which do not intrinsically alter flow.

Arterio-venous shunting complicating occlusive atherosclerotic peripheral vascular disease.

Three cases of severe occlusive peripheral vascular disease are described in which spontaneous arterio-venous fistulae at the site of atheromatous occlusion have been demonstrated by angiography during the arterial phase. Although none of these patients exhibited specific clinical signs of an arterio-venous fistula, this phenomenon is considered to have been a clinically significant factor in the patients' peripheral ischaemia. In one case both the superficial femoral artery stenosis and the spontaneous shunts were effectively treated by percutaneous angioplasty.

Outcome of TIAs of unknown aetiology following non-invasive evaluation.

A proportion of patients with apparently classical transient ischaemic attacks (TIA), will have no cause for their symptoms discovered when investigated. We have reviewed 74 patients with TIA and a further 28 with amaurosis fugax whose symptoms remained unexplained following non-invasive carotid evaluation using pulsed Doppler imaging with spectrum analysis. After a mean follow-up of 31.7 months, 48.6% of TIA patients were symptom free, 36.5% had experienced recurrent symptoms and 8.1% had suffered a stroke. Among the patients with amaurosis fugax the equivalent figures were 32.1% symptom free, 42.7% recurrent symptoms, and 10.7% stroke. These figures suggest that unexplained TIAs do not necessarily have a benign prognosis and more extensive or repeated investigation of these patients is warranted.

Role of arteriography in the selection of patients for carotid endarterectomy.

BACKGROUND: Duplex ultrasonography is used increasingly to select patients for carotid endarterectomy. This study aims to clarify whether arteriography is still required. METHODS: A total of 272 patients in whom duplex imaging indicated significant disease of the internal carotid artery underwent arteriography and the results were compared. Regarding the arteriogram as the 'gold standard', three aspects were considered: the accuracy of duplex ultrasonography in detecting significant stenosis, the ability of duplex imaging to identify patients who should have arteriography and whether the arteriogram provided important additional information that might influence a decision to operate. RESULTS: Three patients (1 per cent) suffered a permanent neurological deficit as a result of arteriography. Of the 272 patients with significant stenosis identified by duplex ultrasonography, 241 (89 per cent) were confirmed as significant on arteriography. Duplex imaging was not able to predict accurately which arteriograms would provide useful additional information (sensitivity 59 per cent, specificity 65 per cent), whereas 89 arteriograms (33 per cent) contained information that might have influenced subsequent management. CONCLUSION: Duplex imaging is unable to detail the anatomy or determine the extent of carotid disease and may therefore lead to an inappropriate decision to perform carotid endarterectomy. Duplex imaging alone is not adequate before carotid endarterectomy.

Haemodynamic assessment following iliac artery dilatation.

Fourteen patients with symptomatic atheromatous stenoses of common or external iliac arteries underwent percutaneous arterial dilatation. Twelve procedures were considered successful in terms of arteriographic and symptomatic improvement but the application of three haemodynamic indices (pressure index, pulsatility index and the papavarine test) indicated that only 8 patients had gained a significant improvement in blood flow. These results illustrate the need for quantitative measurements in the assessment of this new technique.

Detection of intracranial emboli in patients with carotid disease.

Transcranial Doppler emboli signal detection has been reported in several patient groups, including patients with symptomatic internal carotid artery stenosis. The potential of this technique in assessing embolic risk and selecting patients for surgery was examined in this study. Selected patients with symptomatic internal carotid artery stenosis underwent combined extracranial and transcranial Doppler study in the Vascular Surgery and Neurovascular Unit. Patients and normal controls were monitored with transcranial Doppler over both middle cerebral arteries. Severity of carotid disease was diagnosed with colour Duplex ultrasound examination or angiography. Selected patients underwent cranial computed tomography and transthoracic echocardiography. Patients undergoing carotid endarterectomy were re-examined one month after surgery. Fifty symptomatic patients, six asymptomatic patients and 30 normal controls were examined. Carotid disease was unilateral in 34 and bilateral in 22 cases. Emboli signals were detected in 94% of patients. The emboli signal count in patients with unilateral carotid stenosis was significantly higher in the middle cerebral artery distal to the stenosed internal carotid compared to the contralateral middle cerebral artery [14 (10-22) versus 2 (0-7) signals per hour, median and 95% confidence intervals, p < 0.001] and in symptomatic compared to asymptomatic cerebral hemispheres [15 (11-21) versus 4 (2-9) signals per hour, p < 0.001]. Emboli were detected in the contralateral middle cerebral artery in 40% of patients with unilateral carotid disease, in 85% of whom an additional embolic source was identified. No emboli signals were detected after carotid endarterectomy distal to the operated internal carotid, or in any of the normal controls. In conclusion, intracranial emboli signals are common in patients with carotid stenosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Renal transplantation: an analysis of 33 cases.

Thirty-three patients with end-stage renal failure have had transplants over a three-year period, four patients receiving kidneys from siblings and the remainder cadaver organs. Twenty-seven kidneys survived with stable function for periods of six months to three years. Graft survival at one year was 85% and at two years 82%. One patient died and five were returned to dialysis. Complications included rejection episodes, technical problems, respiratory and wound infections, gastrointestinal disorders, and side effects of steroids.