Though classically rare, dissections of extracranial

Transcription

1 11 Duplex Scannng n Extracranal Vertebral Artery Dssecton Perre-Jean Touboul, MD, Jean-Lous Mas, MD, Mare-Germane Bousser, MD, and Domnque Laplane, MD Ultrasonc (duplex scannng and contnuous-wave Doppler) and angographc fndngs n three patents wth blateral extracranal vertebral artery dssecton are reported. A pattern of ultrasonc anomales dagnostc of dssecton s descrbed, ncludng assocaton of a localzed ncrease n dameter of the artery wth hemodynamc sgns of stenoss or occluson at the same level and decreased pulsatlty and presence of ntravascular echoes n the enlarged segment. (Stroke 1987;18:11-121) Though classcally rare, dssectons of extracranal vertebral arteres are ncreasngly reported. 1 " 5 Ther dagnoss reles manly on suggestve angographc anomales (such as long and rregular stenoss or double lumen 1 " 5 ) that usually dsappear n a few weeks, thus a posteror confrmng the dagnoss. Repeated arteral assessment s therefore mportant n ths condton but cannot easly be performed wth conventonal angography; therefore, dgtzed ntravenous angography was found useful n ths respect. Ths study dscusses the value of ultrasonc examnaton n both the dagnoss and follow-up of extracranal vertebral artery dssectons. Subjects and Methods Three patents wth blateral extracranal vertebral artery dssectons were studed. Snce clncal and angographc fndngs have been fully reported n a prevous paper 7 (Cases, 7, and 8), only a bref summary wll be gven. Ultrasonc examnaton was performed usng both contnuous-wave Doppler and duplex scannng. Contnuous-wave Doppler was conducted wth a 4-MHz probe; velocty curves were recorded at the suboccptal segment. Duplex scannng equpment (Bosound, Indanapols, Indana) ncludes a system for magng arteral walls and ther contents (B-mode echo) and a pulsed Doppler wth a 1-mm sample volume for analyss of flow velocty wherever blood vessels are vsualzed. Ths equpment has prevously been extensvely descrbed 8 together wth the examnaton procedure for vertebral arteres, and such an examnaton has been shown to assess relably normal extracranal vertebral arteres. 8 " 1 In the present study, the followng four parameters were systematcally recorded for both vertebral arteres n ther pretransverse (from orgn to C) and and C5-C4 ntertransverse segments: dameter n mm, pulsatlty (systolc expanson), presence or From the Clnque dcs Malades du Systeme erveux, Hdptal de la Salpetrerc (P.-J.T., M.-G.B., D.L.), and the Servce de eurologe, Centre Raymond Garcn, Hdptal Sante-Anne (J.-L.M.), Pars, France. Address for correspondence: Perre-Jean Touboul, 58 rue Perre Charron, 758 Pars, Cedex 1, France. Receved February 2, 1987; accepted July 22, absence of ntravascular echoes, and pulsed Doppler sgnal. Ultrasonc fndngs were compared wth angographc data obtaned at the tme of dssecton n all patents and durng follow-up n two. The nterval between angographc and ultrasonc study was <2 weeks n all cases. Results Patent 1 A 2-year-old woman had a left lateral medullary syndrome preceded by neck pan on March 25, 198. Blateral brachal angography on March, 198, showed an rregular stenoss of the second and thrd segments of the rght vertebral artery wth an aneurysmal dlataton at the Cl level (Fgure 1, rght). The dstal ntracranal vertebral artery and the baslar artery were not flled by the rght vertebral artery. The left vertebral artery was rregularly stenosed n ts second and thrd segments; ts ntracranal segment and the baslar artery were thn but ther walls were regular (Fgure 1, left). On the dgtzed ntra-arteral angography performed on December 12, 198, the left vertebral artery was normal, but the rght one was not opacfed wth certanty. The frst ultrasonc study was performed 2 weeks after the onset of schemc symptoms, 1 days after angography. On contnuous-wave Doppler, no sgnal was recorded on the rght sde and only a weak one was present on the left. On duplex scannng, the rght vertebral artery appeared normal from ts orgn to a few mllmeters below ts entry nto the transverse foramen of C, but mmedately above and n ts and C5-C4 portons, the dameter of ths vessel was ncreased to 5.5 mm (Fgure 2), ts pulsatlty was decreased, and ntravascular echoes were observed. Pulsed Doppler was audble n the frst segment but ts ampltude was low, wthout dastolc component; t was not audble n the and C5-C4 segments. B- mode and pulsed Doppler fndngs were absolutely dentcal for the left vertebral artery. The second ultrasonc study was performed 4 weeks later. o change was observed on the rght sde, whereas the left sde had returned to normal. The thrd ultrasonc study was performed 7 months later, 2 days after the control angography. The rght

2 Touboul et al Duplex Scannng n VA Dssecton 117 FIGURE 1. Left and rght brachal angograms ofpatent 1, March,198. Left: Irregular stenoss of second and thrd segments of left vertebral artery. Rght: Irregular stenoss of second and thrd segments of rght vertebral artery wth aneurysmal dlataton at Cl level (open arrow). vertebral artery showed sgns of occluson: no pulsatlty and no audble sgnal on pulsed Doppler. Furthermore, the dameter of the artery was reduced to 2 mm, and the ntravascular echoes had a hgher echogencty and were also noted n the pretransverse porton (Fgure ). The left vertebral artery was normal, thus confrmng angographc fndngs. Patent 2 A 2-year-old woman had a mnor baslar stroke preceded by neck pan on July 8, 198. Blateral brachal angography on July 2, 198, showed a severe and rregular stenoss of the second segment of the rght vertebral artery and of the second and proxmal thrd segments of the left vertebral artery wth renjecton of the dstal part of both vertebral arteres va muscular arteres. The frst ultrasonc study was performed 1 days after the onset of symptoms, 5 days before angography. On contnuous-wave Doppler, a weak sgnal was recorded on both sdes. On duplex scannng, only the and C5-C4 portons could be vsualzed. The dameter of both vertebral arteres was mm; pulsatlty was decreased on the rght sde and absent on the left. Intravascular echoes were observed on both sdes. Pulsed Doppler was weakly audble on the rght sde and not audble on the left. On the second ultrasonc study, performed 2 months later, both vertebral arteres appeared normal. Patent A 27-year-old woman had a mnor baslar stroke on December 1, 198, 4 days after a chropractc manpulaton of her neck. On transfemoral angography on January, 1984, the rght vertebral artery was occluded from C to C2 and renjected va anastomoss wth muscular arteres. The left vertebral artery was moderately and rregularly stenosed from C to C2. Both vertebral arteres were normal on control dgtzed ntra-arteral arterography performed 5 months later. The frst ultrasonc study was performed 18 days after the onset of symptoms, 11 days after angography. Contnuous-wave Doppler was normal on both sdes. On duplex scannng, the pretransverse rght vertebral artery was normal except for pulsed Doppler,

3 118 Stroke Vol 19, o 1, January 1988 FIGURE 2. Ultrasonc study of Patent 1, Aprl 9, 198. Top: Rght vertebral artery, pretransverse segment; dameter = 5.5 mm (black arrows) just below entry nto foramen of C (scale, 2 mm between vertcal lnes). Bottom: Rght vertebral artery, ntertransverse segment; dameter = 5.5 mm (black arrows), ntravascular echoes (whte arrows).

4 Touboul et al Duplex Scannng n VA Dssecton 119 FIOURE. Ultrasonc study of Patent 1, December 14, 198. Top: Rght vertebral artery, ostum and pretransverse segment; dameter = 2 mm (arrows), ntravascular echoes. Bottom: Left vertebral artery, ntertransverse segment; dameter=4 mm (arrows).

5 12 Stroke Vol 19, o 1, January 1988 whch was weakly audble. At the and C5-C4 levels the dameter was ncreased to mm, the pulsatlty was decreased, and pulsed Doppler was only weakly audble. On the left sde, the pretransverse segment was normal, but at the and C5-C4 levels the dameter was ncreased to 5 mm, the pulsatlty was decreased, and ntravascular echoes were present; pulsed Doppler was normal, however. The second ultrasonc study was performed weeks later. The rght vertebral artery was unchanged except for a decrease n dameter to 5 mm at the and C5-C4 levels; the left had returned to normal. Both vertebral arteres were normal on the thrd study weeks later. Summary Ultrasonc and angographc fndngs at the tme of dssecton are summarzed n Table 1. Increased dameter and decreased pulsatlty were observed n the sx vertebral arteres. Intravascular echoes were observed n fve and the pulsed Doppler sgnal was dmnshed or absent n fve. Contnuous-wave Doppler sgnal was decreased or absent n four and normal n two. Control ultrasonc examnaton showed a return to normal n fve vertebral arteres and an occluson n one. Ths correlates well wth angographc data n the two patents who had control angography, whch showed a return to normal n three vertebral arteres and probable occluson n one. Dscusson The present study shows a dstnctve ultrasonc pattern n extracranal vertebral artery dssecton, namely, Table 1. Summary of Ultrasonc and Angographc Fndngs at Tme of Dssecton Patent 1 Patent 2 RVA LVA RVA LVA Contnuous-wave Doppler (suboccptal recordng) B-mode Dameter (mm) Pulsatlty Intravascular echo Pulsed Doppler Angography 5.5 o I C to Cl stenoss o I C to Cl stenoss ncreased arteral dameter assocated wth decreased pulsatlty, presence of ntravascular echoes, and hemodynamc sgns of stenoss or occluson. For the dameter to be descrbed as "ncreased" mples knowledge that the artery s not smply large ether physologcally or pathologcally, as n dolchomega vertebral artery. Ths knowledge can be obtaned n two ways: frst, when the ncrease n dameter s localzed, as occurred here wth an abrupt ncrease n arteral calber from to 5 or mm; and second, when t s reversble, agan noted n the present study. Decreased pulsatlty n the enlarged segment contrastng wth normal pulsatlty n the predssected segment agan mght help to dfferentate vertebral artery dssecton from other condtons wth large vertebral arteres but normal pulsatlty, such as dolchomega arteres. However, ths s a judgmental decson n the test and requres an experenced techncan. Intravascular echoes are not observed n normal arteres. They ndcate the presence of an abnormal structure ether n the arteral lumen or n the vessel wall. Progress n ultrasonc technology wll probably allow dfferentaton between these two possbltes. Whle the prevous factors are all determned by B- mode scannng, contnuous-wave Doppler and pulsed Doppler are necessary to detect hemodynamc sgns of stenoss, whch classcally consst of a decreased Doppler sgnal proxmal to the stenoss, an ncreased sgnal n the resdual lumen, and a decreased sgnal dstal to the stenoss. In the present study, an ncreased sgnal n the enlarged segment was never observed ether because of the mpossblty of detectng a small resdual lumen or because of the actual characterstcs of stenoss n dssectons, namely, ts tghtness and I CtoC2 stenoss C to Cl stenoss Patent RVA LVA 1 o o 1 C to C2 occluson RVA, rght vertebral artery; LVA, left vertebral artery;, absent;, normal;, decreased. 5 1 o C to C2 stenoss

6 Touboul et al Duplex Scannng n VA Dssecton 121 extent. Pulsed Doppler sgnal proxmal to the stenoss and contnuous-wave Doppler dstal to t were not decreased n one patent. As suggested by angography, ths was probably due to the presence of only moderate stenoss on one sde and to the development of a rch collateral crculaton on the other. Hemodynamc sgns can therefore be absent n extracranal vertebral artery dssectons. As llustrated n the present study, ultrasonc examnaton s an excellent tool wth whch to apprecate the evoluton of dssecton. The examnaton was performed before the end of the frst month n two patents and already showed mprovement or return to normal, whch was later confrmed by angography. How early mprovement starts and normalzaton s acheved remans unknown, although t s well establshed that the majorty of dssected vertebral arteres return to normal wthn months. 7 To conclude, the present study descrbes for the frst tme a pattern of ultrasonc anomales dagnostc of extracranal vertebral artery dssecton, namely, the assocaton of a localzed ncrease n arteral dameter wth hemodynamc sgns of stenoss or occluson and/ or decreased pulsatlty and ntravascular echoes at the same level. Furthermore, t outlnes the utlty of repeated ultrasonc examnaton n the follow-up of arteral changes n dssectons. References 1. Hart RG, Eastern JD: Dssectons of cervcal and cerebral arteres. eurol Cln 198;1: Katrj MB, Renmuth OM, Latchaw RE: Stroke due to vertebral artery njury. Arch eurol 1985;42: Hart RG, Easton JD: Dssectons. Stroke 1985;1: Caplan LR, Zarns CK, Hemmat M: Spontaneous dssecton of the extracranal vertebral arteres. Stroke 1985;1: Bller J, Hngtgen WL, Adams HP, Smoker WRK, Godersky JC, Toffol GJ: Cervcocephalc arteral dssectons. A ten-year experence. Arch eurol 198;4: Mas JL, Goeau C, Bousser MG, Chras J, Verret JM, Touboul PJ: Spontaneous dssectng aneurysms of the nternal carotd and vertebral arteres. Two case reports. Stroke 1985;1: Mas JL, Bousser MG, Hasboun D, Laplane D: Extracranal vertebral artery dssectons: A revew of 1 cases. Stroke 1987;18:1O7-1O47 8. Ackerstaff RGA, Hoeneveld H, Slowlowsk JM, Moll FL, Ekelboom BL: Ultrasonc duplex dsease of the nnomnate subclavan and vertebral arteres. Comparatve study wth angography. Ultrasound Med Bol 1984;1: Debray JM, Maugn D, Jeanvone H, Dauzat M, Lhoste P: Etude prospectve sur la valeur clnque de l'exploraton echotomographque des arteres vertebrales. JEMU 198;7: Touboul PJ, Bousser MG, Laplane D, Castagne P: Duplex scannng of normal vertebral arteres. Stroke 198;17: KEY WORDS ultrasonc dagnoss vertebral artery angography