Fibromuscular Dysplasia May Herald Symptomatic Recurrence of Cervical Artery Dissection

BACKGROUND

The prevalence of fibromuscular dysplasia (FMD) in patients with cervical artery dissection (CAD) is unknown. Our objectives were to assess the risk of CAD recurring as a stroke or a transient ischemic attack and the association of these events with FMD.

METHODS

We prospectively included and followed 103 consecutive patients who had been admitted for a CAD. The median follow-up was 4 years (range 4 months to 10 years). The main criteria for inclusion were a mural hematoma demonstrated by cervical magnetic resonance imaging and/or signs suggesting CAD on 2 other investigations. FMD was diagnosed on the so-called string of beads pattern by digital subtraction angiography.

RESULTS

Five patients had CAD recurrence (60% occurred late). Four of these 5 patients had FMD. In 4 patients, CAD recurrence involved another cervical artery.

CONCLUSION

The rate of symptomatic CAD recurrence was 1% per year and was often related to FMD.

Palladium-catalyzed synthesis of 2,3-dihydro-2-ylidene-1,4-benzodioxins

Palladium-catalyzed condensation of benzene-1,2-diol with various propargylic carbonates afforded regio- and stereoselectively 2,3-dihydro-2-ylidene-1,4-benzodioxins. The reaction is suggested to proceed by the formation of a (sigma-allenyl)palladium complex, followed by the intermolecular attack of the phenoxide ion on this complex to generate a new (sigma-allyl)palladium complex in equilibrium with the corresponding (eta(3)-allyl)palladium complex. Intramolecular attack of the phenoxide ion afforded the corresponding benzodioxan compound. This last attack occurs predominantly at the more electrophilic end of the (eta(3)-allyl)palladium intermediate. The Z- or E-stereochemistry of the products was established by (1)H NMR and proton NOE measurements and also by X-ray analysis on an example. The Z-stereochemistry generally observed is in agreement with the formation of this (eta(3)-allyl)palladium intermediate. However, in the case of tertiary propargylic carbonates, the E-stereochemistry generally observed could be explained by an intramolecular attack of the phenoxide ion on the intermediate (sigma-allyl)palladium complex, in slow equilibrium with the (eta(3)-allyl)palladium complex.

Detection of vertebrobasilar intracranial stenoses: transcranial Doppler sonography versus angiography

Vertebrobasilar intracranial stenoses seem to carry a higher risk of brain stem ischemia than proximal vertebral artery stenoses. Our aim was to assess the value of transcranial Doppler sonography versus angiography in detecting and quantifying these intracranial stenoses. All consecutive patients who underwent transcranial Doppler sonography prior to angiography from 1989 to 1994 and whose sonograms showed a stenosis of greater than 50% of one vertebral artery (21 cases) or of the basilar artery (eight cases) were included in the study. These patients were compared with 60 other consecutive stroke patients studied via transcranial Doppler sonography prior to normal vertebrobasilar angiography The transcranial Doppler sonographic criteria for stenosis were a peak systolic frequency shift greater than 2 KHz. A tight stenosis was identified by this pattern combined with direct and reverse low frequencies of high spectrum energy. The sensitivity of transcranial Doppler sonography using a peak systolic frequency shift in diagnosing stenoses reached 80% and its specificity was 97% if only atheromatous stenoses were considered. The main diagnostic failures concerned bilateral stenoses or contralateral occlusion, tandem lesions, and upper basilar artery stenosis. Transcranial Doppler sonography underestimated the degree of stenosis compared to angiography in 55% of the cases. We conclude that transcranial Doppler sonography is accurate in recognizing a stenosed vessel in the intracranial vertebrobasilar circulation, but if this finding will alter therapy, the examination must be complemented by magnetic resonance angiography.

Colour Doppler and duplex sonography and angiography of the carotid artery bifurcations. Prospective, double-blind study

We undertook a prospective double-blind study of 128 carotid artery bifurcations using colour Doppler and duplex sonography and angiography. Sixty-four patients with cerebrovascular events were admitted for angiography. All underwent sonography within 24 h of angiography. Standard duplex sonography and colour Doppler imaging without spectral analysis were performed, on the same device, by two sonographers, using defined morphological and haemodynamic criteria. Digital radiological data on vessel diameter were interpreted independently by two radiologists. The two sonographic methods gave similar grading of stenosis, compared to angiography, with an accuracy ranging from 96% in severe to 83% in minor stenoses. Colour Doppler studies gave better area measurements than standard duplex sonography, except for major stenoses. Discrepancies between ultrasonography and angiography were due mainly to minor stenoses and large plaques of calcification on the vessel walls, which masked very segmental 70% stenoses in 2 cases. Angiography is limited by its own resolution, does not show uncalcified vessel walls and does not give cross-sectional data. It would therefore be inappropriate for showing small plaques, the full extent of ectasia or for defining the carotid bulb accurately. The advantages of colour methods were in investigating sinuous or deep vessels and hypoechoic plaques. Analysis of the residual lumen of a stenosis and its extent could be determined more rapidly. Haemodynamic quantification of stenoses by standard duplex sonography may be difficult because of limited sample volume and error in estimation of angle, whereas colour Doppler allows semiquantitative estimation of haemodynamics.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of subclavian syndrome on the basilar artery

Fifty-five patients with a permanent or intermittent subclavian steal syndrome demonstrated by continuous wave Doppler were included in a prospective study: 25 patients without vertebro-basilar symptoms, 8 symptomatic patients with defined vertebro-basilar symptoms and 22 with hemodynamic vertebro-basilar occurrences. The basilar artery velocity was recorded by Transcranial Doppler Sonography in baseline conditions, and after a hyperaemia test to the upper limb. A spontaneous, incomplete basilar steal was diagnosed in seven patients, and a complete basilar steal in one patient, (14.5% of the cases). After hyperaemia test, 18 other incomplete basilar steal were observed. The occurrence of a basilar steal was higher in the vertebro-basilar group (57% of the cases) especially in 7 of the 8 cases with defined vertebro-basilar symptoms; it was lower in the patients without vertebro-basilar occurrences (36% of the cases). This basilar steal was also seen in five of the six symptomatic patients with opposite vertebral artery stenosis above a 50% diameter. Transcranial Doppler Sonography could help to define a subgroup of subclavian steal syndrome with a high risk of strokes.

Ultrasonic features of extracranial carotid dissections: 47 cases studied by angiography

The purpose of this prospective study was to assess the value of continuous wave Doppler velocimetry, standard duplex scanning and color Doppler flow imaging in the diagnosis of carotid dissections. From 1975 to 1993, 42 patients (mean age, 44 +/- 14 years) were admitted to the University Hospital of Angers for a carotid dissection studied first by ultrasonography, then defined by angiography. Five cases were bilateral. Continuous wave Doppler examination revealed signs of severe obstruction of the carotid arteries in 96% of the cases (occlusion, extensive submandibular tight stenoses, significant slowdowns in the carotid and ophthalmic vessels, retrograde ophthalmic blood flow). Standard duplex scanning suggested dissection in 72% of the cases (tapering stenoses or occlusion, segmental ectasis, tubular vessel, peripheral residual channel, or rare irregular "membrane"). Color Doppler flow imaging suggested a dissection in 82% of the cases. This method has the advantage of underlining the peripheral channel, the double lumen, and the dissecting hematoma, which often is hypoechoic. The ultrasonic methods (continuous wave Doppler combined with color Doppler flow imaging) failed only when they are performed late and when moderate or segmental intrapetrosal dissections were present. These ultrasonic investigations would thus appear to be useful for early diagnosis of carotid dissections.

[Doppler transcranial ultrasonography in carotid and vertebral dissections: 36 cases involving angiography]

The aim of this prospective study was to investigate the additional information provided by transcranial pulsed Doppler for the determination of the upper part of dissections of the carotid and vertebral arteries and following-up. Earlier results concerning the role of ultrasound investigations for this indication have been presented elsewhere. Twenty-nine patients were examined (17 females, 12 males; mean age 43 years). All had arterial dissections confirmed by arteriography. There were 24 carotid dissections and 12 vertebral dissections. Investigations were performed during the acute phase and 2 months later. Most of the severe endocranial stenoses were identified by transcranial Doppler: 5 out of 6 severe stenoses of the carotid siphon and 6 out of 7 vertebral stenoses. The haemodynamic effect as measured by sylvian flow was significantly greater (p < 0.01) after a permanent ischaemic event than after temporary events and improved significantly with time (p < 0.008). There was no significant variation in the pulsatility transmission index (PTI), but this index requires a reference artery and is not particularly adapted in cases with bilateral dissection. Collateral perfusion, observed during the acute phase in all cases of occlusion and in 6 of the 8 carotid stenosis, was insufficient in half of the cases. Transcranial pulsed Doppler can be used to guide arteriography and helps determine the length of the dissection. It provides an easy way to assess the haemodynamic consequences of the dissection and is quite useful during follow-up.

[Arterial vascularization of the colon. The middle mesenteric artery]

In its modal disposition, the arterial vascularisation of the colon is on the dependence of the superior and inferior mesenteric arteries anastomosed by the way of "arcade de Riolan". Some more exceptional schemes can complicate this distribution: arteria colica media, medium mesenteric artery, intermesenteric arcus. This rare arterial dispositions can have a big practical importance, in the case of colic transposition, and more recently in the case of the utilization of the right gastroepiploic artery for coronary by-pass.

[Primary aortoduodenal fistula of tuberculous origin]

This case of aorto-duodenal fistula was due to fistulization of a tuberculous lymph node between an atheromatous aneurysm of the infra-renal aorta and the third part of the duodenum. CAT scan provided the diagnosis of an aorto-duodenal fistula. The tuberculous origin of the fistula was confirmed by bacteriological and histological examinations. The outcome was favourable after revascularisation "in situ" combined with epiplooplasty and prolonged antituberculous drug therapy.

Endofibrosis of the external iliac artery in bicycle racers: an unrecognized pathological state

Since December 1985, we have operated upon seven bicycle racers for endofibrosis of the external iliac artery. In all instances, the athletes had started cycling early in life and were engaged in top level competition by the age of 17. The principal complaint was intermittent claudication of one lower limb at "near-maximal" exercise. Pain could be reproduced by exertional tests on an ergometric bicycle, and in all cases except one, measurement of ankle systolic pressure of that limb compared with the opposite side and brachial pressures showed a marked decrease on the involved side. Arteriography, performed with multiple views and positions, documented a 5 to 6 cm moderately stenotic (less than 40% diameter) segment, associated with arterial lengthening. Surgical treatment consisted of endarterectomy and shortening of the artery. Four patients were able to return to competition. The origin of this pathology is discussed, based on gross and histologic findings. Under certain predisposing anatomic conditions, abnormal hemodynamics, probably due to a high flow arterial state and an aerodynamic position on the bicycle, provoke repeated trauma which eventually produces the lesion. Practically unrecognized until now with only two previous publications on the subject in the literature, this entity is probably not uncommon.

[Noninvasive methods in the diagnosis of post-infarction false aneurysm. Apropos of a case]

A case of post-aneurysm detected by chance in an asymptomatic 41 year old man, 3 months after acute infarction, and managed by surgery is reported. Although the aneurysm was too small to cause chest X-Ray changes, the parietal defect was clearly defined by isotopic angioscintigraphy, CAT scanning and M-mode echocardiography. The features of pseudo-aneurysms on CAT scanning are discussed. The value of M-mode echocardiography is confirmed, it alone giving the precise diagnosis through the demonstration of one dynamic sign: systolic expansion of the aneurysmal pocket on a tracing more suggestive of a localised pericardial effusion than of ventricular aneurysm. Early diagnosis by these non-invasive methods of investigation, requested as a result of some initial clinical abnormality, confirmed by angiography, may benefit some patients as the risk of secondary rupture may be avoided by surgical cure. The rarity of this condition is also under question due to the increasing number of reported cases.

[Intensive fattening of Adamaoua zebus. II. Influence of duration of breeding period (1971)]

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