Carotid angioplasty with internal carotid artery flow reversal is well tolerated in the awake patient

OBJECTIVE: The purpose of this study was to evaluate the neurologic tolerance and changes in ipsilateral hemispheric oxygen saturation during transcervical carotid artery stenting with internal carotid artery (ICA) flow reversal for embolic protection. PATIENTS AND METHODS: This was a prospective study of 10 patients (mean age 68 years) undergoing transcervical carotid angioplasty and stenting. All ICA stenoses were greater that 70%. Seven patients had an ipsilateral hemispheric stroke (3) or transient ischemic attack (4), two patients had a contralateral stroke, and one patient was asymptomatic. Nine procedures were done under local anesthesia. Cerebral protection was established through a cervical common carotid (CCA) cutdown to create an external fistula between the ICA and the internal jugular vein with temporally CCA occlusion. Venous oxygen saturation (SVO(2)) was continuously monitored through a catheter placed in the distal internal jugular vein. Mental status and motor-sensory changes were categorized and assessed throughout and after the procedure. RESULTS: All procedures were technically successful without significant residual stenosis. Mean ICA flow reversal time was 22 minutes (range, 15 to 32). Common carotid artery (CCA) occlusion produced a slight (SVO(2) = 72.6%+/-9.4) but significant decrease (P =.012) in SVO(2), compared with baseline (SVO(2) = 77% +/-10.5). During ICA flow reversal (SVO(2) = 72.4% +/-10.1) cerebral oxygen saturation did not change compared with CCA occlusion alone (P =.85). Transient balloon occlusion during angioplasty of the ICA (SVO(2) = 64.6%+/-12.9) produced a significant decrease in cerebral SVO(2) compared with CCA occlusion (P =.015) and compared with CCA occlusion with ICA flow reversal (P =.018). No mental status changes or ipsilateral hemispheric focal symptoms occurred during CCA occlusion with ICA flow reversal. One patient with contralateral ICA occlusion sustained brief upper extremity weakness related to the contralateral hemisphere. Five patients sustained a vasovagal response during balloon dilatation, four did not require treatment, and one had asystole requiring atropine injection. Mean SVO(2) saturation was not different in these five patients compared with the five who did not sustain a vasovagal response. No deaths or neurologic deficits occurred within 30 days after the procedure. CONCLUSIONS: Our data suggest that transcervical carotid angioplasty and stenting with ICA flow reversal is well tolerated in the awake patient, even in the presence of symptomatic carotid artery disease. Cerebral oxygenation during ICA flow reversal is comparable to that during CCA occlusion. ICA angioplasty balloon inflation produces a decrease in cerebral SVO(2) significantly greater than that occurring during ICA flow reversal.     

Hemodynamic conditions at the carotid bifurcation during protective common carotid occlusion.

OBJECTIVES: Carotid angioplasty and stenting procedures are associated with an obligatory release of particulate debris into the distal cerebral circulation. Although most of the emboli are small and do not result in symptomatic neurologic deficits, some may be large enough to cause stroke. For this reason, a variety of filters and balloon occlusion devices have been employed as adjuvants to decrease the risk of distal embolization during carotid stenting. Some of these devices rely on the arrest of antegrade blood flow with the use of inflow arrest. The present study was undertaken to investigate the hemodynamic conditions that exist at the carotid bifurcation during common carotid artery (CCA) occlusion. METHODS: Internal carotid artery (ICA) and external carotid artery (ECA) stump pressures were measured in 29 patients undergoing carotid endarterectomy. Duplex ultrasound scanning was used to measure the direction and velocity of blood flow in the ICA and ECA with the CCA cross-clamped but the ICA and ECA open, a clinical scenario analogous to CCA balloon occlusion at the time of carotid angioplasty and stenting. The direction and magnitude of ICA and ECA flow were compared with the stump pressures to determine whether a correlation existed between these variables. RESULTS: The mean stump pressure in the ICA and ECA averaged 56 +/- 16 and 53 +/- 12 mm Hg, respectively. The ICA systolic stump pressure was lower than the ECA systolic stump pressure in six patients (21%), and all of these patients had persistent antegrade systolic duplex blood flow by duplex interrogation during CCA occlusion. The ICA systolic stump pressure exceeded the ECA systolic stump pressure in 19 patients (66%), and all of these patients had retrograde ICA flow during systole. Diastolic flow was also well correlated with the magnitude of the ICA/ECA stump pressure differential, with antegrade diastolic ICA blood flow in all nine patients with an ICA diastolic stump pressure less than the ECA diastolic stump pressure. None of the 10 patients with ICA diastolic stump pressure greater than ICA diastolic stump pressure maintained antegrade ICA diastolic flow, but four of these patients had flow to zero in diastole. Overall, 13 of 29 patients (45%) could be surmised to be at risk for distal embolization to the brain based on the persistence of some element of either systolic or diastolic antegrade ICA flow during common carotid occlusion. CONCLUSIONS: Common carotid occlusion alone appears insufficient to protect against distal embolization during manipulations of the carotid bifurcation. Persistent systolic or diastolic antegrade blood flow occurs in a high proportion of patients, lending credence to the use of additional protective strategies to ameliorate the risk of embolic complications.     

Protection of anastomotic pathways to the vertebral artery during stenting of external carotid artery stenosis

A 61-year-old man presented with a severe external carotid artery (ECA) stenosis with concomitant ipsilateral internal carotid artery (ICA) occlusion manifesting as amaurosis fugax. The left ophthalmic artery was supplied from the left ECA. The left intracranial ICA was supplied by the collateral flow from the contralateral ICA and ipsilateral ECA through the ophthalmic artery. The left vertebral artery also participated in the latter collateral pathway through the left occipital artery and ascending pharyngeal artery. Percutaneous revascularization of the ECA was performed using a nitinol self-expanding stent. To prevent embolic complications through the ophthalmic or vertebral arteries, distal protection was performed using a balloon. During a 22-month follow-up period, the patient was completely free from any ocular or neurological symptoms. The present case of severe ECA stenosis with ipsilateral ICA occlusion showed that percutaneous balloon angioplasty with stenting is feasible and effective. This intervention requires cautious evaluation of the anastomotic pathways connecting the ECA to the cerebral circulation to avoid embolic complications.     

Cerebral protection during retrograde carotid artery stenting for proximal carotid artery stenosis: technical note

Carotid artery stenting for carotid bifurcation stenosis usually uses the transfemoral approach. However, in patients with proximal common carotid artery (CCA) stenosis, the guiding catheter is difficult to introduce into the narrow origin of the CCA without risking cerebral embolization before activation of the protection device. A technique of cerebral protection by internal carotid artery (ICA) clamping with or without simultaneous external carotid artery (ECA) clamping was used to treat patients with proximal CCA stenosis by the retrograde direct carotid approach. The carotid bifurcation was surgically exposed and retrograde catheterization was performed to approach the stenosis. The ICA was clamped during angioplasty and stenting to avoid cerebral embolization. The ECA was clamped simultaneously if any extracranial-intracranial anastomosis was present. None of five patients treated with this technique experienced ischemic complications attributable to this technique.     

Results of endovascular treatment of internal carotid artery stenoses with a newly developed balloon protection catheter

OBJECTIVE: A new balloon protection catheter to prevent distal emboli during internal carotid artery percutaneous transluminal angioplasty and stenting was developed, and its efficacy was evaluated in both an experimental model and clinical cases. METHODS: The balloon protection catheter was navigated over a steerable 0.014-inch guidewire to negotiate tight stenoses and sharp bends, which would cause difficulties for the passage of a flow-directed balloon catheter. Percutaneous transluminal angioplasty and stenting were performed for 85 consecutive patients with 87 stenotic lesions of the cervical internal carotid artery, with two different methods using this protection system. Distal protection was provided only after dilation for the initial 38 lesions (Group I), but the latter 49 lesions were treated in both the pre- and postdilation periods (Group II). The effects of using the balloon protection catheter with the embolic debris clearance technique were evaluated with pre- and postoperative magnetic resonance imaging for each group. RESULTS: The balloon protection catheter was introduced beyond the stenosis in all cases. In Group I, one symptomatic embolic stroke was caused by distal embolization resulting from atheromatous plaque, and high-intensity areas appeared on diffusion-weighted magnetic resonance imaging scans in 47% of cases. In contrast, in Group II, there were no strokes related to the procedure, although one patient with multiple risk factors died suddenly on the second day after stenting. Diffusion-weighted imaging scans demonstrated small, high-intensity areas in 19% of cases in Group II. The overall morbidity/mortality rate in our series was 2.3%. CONCLUSION: Our new balloon protection catheter was reliably navigated across internal carotid artery stenoses and reduced distal embolism in clinical cases.     

Common carotid occlusion. Assessment of the distal vessels

In patients with common carotid artery (CCA) occlusion, successful vascular reconstruction can be performed if there is a patent internal or external carotid distal to the occlusion. Preoperative selection of suitable candidates is often difficult because of the inability to visualize patent distal vessels with conventional angiography. In reviewing 24 patients operated upon for CCA occlusion since 1962, the distal internal or external carotid arteries were visualized in only four (17%) of the preoperative angiograms. When these 24 patients were explored, the internal carotid was found to be patent in 11 (46%) patients and the external patent in 15 (62%) cases. Of the 15 patients reconstructed, thromboendarterectomy was performed in six and saphenous vein bypass in nine. In the remaining nine patients, exploration revealed both the internal and external carotids to be thrombosed and unsuitable for CCA reconstruction. Recently we have used rapid sequential computerized tomography (RSCT) scanning to aid in the evaluation of the nonvisualized internal carotid artery (ICA). In two patients with CCA occlusion, RSCT correctly diagnosed patency of the ICA although it appeared to be occluded on angiography. Preliminary data suggest that RSCT will permit accurate preoperative selection of those CCA occlusion patients who are suitable surgical candidates and eliminate the need for surgical exploration.     

Carotid artery stenting using the proximal or dual protection method for near occlusion of the cervical internal carotid artery

The treatment for patients with near occlusion of the cervical internal carotid artery (ICA) is controversial. The aim of this study was to examine the results of carotid artery stenting (CAS) as a surgical treatment for ICA near occlusion. Between April 2008 and September 2012, 14 patients (all men; mean age, 75.4 years) with ICA near occlusion were treated with CAS. This represents 5.2 % of a total of 267 patients treated with CAS during the study period. All patients were treated with CAS using an embolic protection device. The proximal balloon protection method was performed in five patients, and the dual protection method using a proximal balloon and distal filter protection was used in nine patients. We examined the change of stenotic lesion, hyperintensity spot in diffusion-weighted imaging (DWI), and perioperative complications after CAS. All near occlusions were successfully dilated. Among 2 of 14 patients, DWI showed 1 and 4 hyperintensity spots. Transient and persistent complications, including neurological deficits, did not occur in any patients. In this small number of cases, CAS using the proximal or dual embolic protection method seems to be a safe and beneficial treatment for ICA near occlusion.     

Transvascular treatment of giant aneurysms of the cavernous carotid and vertebral arteries: Functional investigation and embolization

Functional angiographic investigation and percutaneous embolization using detachable balloons in nine carotid cavernous aneurysms, three petrous aneurysms, one vertebral artery aneurysm, and one posterior inferior cerebellar aneurysm are reported. A double-lumen balloon catheter is used to evaluate acute tolerance to occlusion of the carotid or vertebral arteries. Occlusion is tested under systemic heparinization. Local perfusion of heparinized saline, proximal as well as distal, to the balloon occlusion is used. The procedure was successful in all but one cavernous aneurysm. The arterial lumen was sacrificed in all cases. Clinical improvement occurred in all successful cases. Retroorbital pain was relieved in all. Ocular cranial nerve palsies improved or resolved in most. One delayed ophthalmic episode that improved represents the only complication. No such embolic problems occurred in any case in which the cavernous carotid artery was occluded by balloon trapping. The delayed embolic complications after carotid artery occlusion are related to the collateral vessels to the C-4 and C-5 segments of the artery. Balloon trapping decreases the length of the thrombosed segment and prevents retrograde filling of the aneurysm.     

A case of carotid occlusive disease treated with stenting for recurrence of stenosis: strategy on intolerance to temporary occlusion

Carotid artery stenting has emerged as an acceptable treatment alternative in patient with occlusive carotid bifurcation disease. High-risk surgical candidates have a lower rate of morbidity after carotid artery stenting with distal embolic protection. Among distal protection devices, a Guardwire balloon occlusion is the most frequently employed in Japan. A 79-year-old male who had severe stenosis at the origin of left carotid artery was treated with stenting under Guardwire balloon protection. He was intolerant to carotid artery occlusion and endovascular procedures were performed under intravenous anesthesia or general anesthesia. In addition, he suffered recurrent stenosis seven months after the first procedure and 16 months after second procedure, and underwent repeated intervention. It was considered that the long tortuous lesion was a cause of the recurrent stenosis.     

Combined surgical and endovascular treatment of infected pseudoaneurysm after carotid endarterectomy. Case report

A 67-year-old male presented with a rare pseudoaneurysm caused by infection after carotid endarterectomy (CEA) performed for stenosis of the left internal carotid artery (ICA). Wound infection and recurrent bleeding from the operated ICA developed 1 month after surgery. Serial angiography showed that the post-CEA pseudoaneurysm gradually increased in size. The carotid balloon occlusion test revealed that the patient could not tolerate permanent ICA occlusion because of poorly developed collaterals. Direct surgical exposure of the aneurysm was impossible due to tight adhesion of the surrounding tissue, so common carotid to middle cerebral artery bypass using a radial artery graft was performed followed by ligation of the distal common carotid artery. Subsequently, retrograde blood flow from the ICA to the aneurysm was interrupted by embolization of the external carotid artery coil through the facial artery. Combined surgical and endovascular treatment is a therapeutic option for patients with post-CEA pseudoaneurysm, if either direct or endovascular surgery is unfeasible.     

Combined endovascular and microsurgical approach in the treatment of giant paraclinoid and vertebrobasilar aneurysms

AIM: The aim of this study is to present the application of endovascular intraoperative occlusion of the parent artery during the microsurgical treatment of giant paraclinoidal internal carotid artery aneurysms (ICA) and of complex vertebrobasilar junction aneurysms . METHODS: Five cases of giant paraclinoidal ICA aneury-sms were treated by direct surgical approach. In the operatory room any patient underwent angiography and balloon occlusion test using a mobile digital subtraction angiograph. Thereafter the catheter was left in the aortic arch. Through an extended pterional craniotomy, it was possible to evidentiate the aneurismal sac. The proximal control of the vessel was achieved inflating a double-lumen balloon; clipping of the aneurysm was achieved, because of pressure lowering inside the aneurysm. Also a giant vertebrobasilar junction aneurysm was treated by this combined technique: using a posterolateral approach the control of the omolateral vertebral artery was obtained by temporary clipping above PICA's origin; the control of controlateral artery was obtained inflating a balloon introduced through the femoral artery. These combined manoeuvres determined sac deflation, allowing an easier clipping. RESULTS: Aneurysm obliteration was achieved with preservation of the circulation without complications in all cases. CONCLUSIONS: The endovascular procedure allows safer and reliable proximal control of paraclinoidal ICA and vertebral artery during the microsurgical treatment of paraclinoid and vertebrobasilar junction aneurysms.     

A preparation to study simultaneous arterial and venous thrombus formation in rabbits.

Injury to an artery induces formation of a platelet-rich thrombus, while stasis or trauma to a vein induces a fibrin-rich thrombus. We have implemented preparations for evolving both platelet-rich and fibrin-rich thrombi simultaneously in rabbits for use to define the efficacy of novel antithrombotic agents. For platelet-rich thrombosis, a carotid artery and contralateral jugular vein were dissected and an arteriovenous shunt inserted distally to prevent cerebral infarction during thrombus formation. The shunted artery was then instrumented with a proximal Doppler probe for measuring flow velocity and a distal transluminal needle electrode. Electrical injury to the artery was induced by application of 250 microA of anodal current to the indwelling needle electrode. Thrombotic occlusion was consistently observed within 60 min, permitting measurements of the effects on the incidence and time of occlusion of antithrombotic agents administered over 2 h. For fibrin-rich thrombosis, an external jugular vein was dissected, including the distal bifurcation. One of the branches was catheterized and a copper wire with cotton threads attached was advanced through the catheter into the superior vena cava, allowing exposure of the threads to flowing blood. A 25- to 30-mg thrombus was formed within 2 h, permitting reliable measurements of effects on thrombus weight of antithrombotic agents administered during this interval. Implementing both arterial and venous thrombosis simultaneously did not change measurements compared with either method alone. This approach may facilitate recognition of differences in efficacy of selected agents against thrombi of diverse composition.     

硬脑膜动静脉瘘动物模型的研究

目的 探讨硬脑膜动静瘘（ＤＡＶＦ）的发病机理。方法 （１）对照组：１０条犬,结扎并剪断右侧颈外静脉;（２）实验１组：１５条犬,吻合右侧颈外静脉远心端与以颈总动脉近心端;（３）实验２组：１５条犬,结扎并剪断左侧颈外静脉,然后与实验１组做相同处理。结果 对照组无ＤＡＶＦ发生;实验１组有３条犬发生ＤＡＶＦ;实验２组有１条犬发生ＤＡＶＦ。结论 单纯升高静脉窦内压力可以诱发ＤＡＶＦ。     

Surgical management of acute complications and critical restenosis following carotid artery stenting

Carotid artery angioplasty with stenting (CAS) is being increasingly used in the treatment of extracranial carotid artery stenosis. As in other catheter-based approaches to the treatment of arterial disease, surgical intervention may be required because of either acute complications or correct critical restenosis. We have reviewed our experience managing early complications and critical in-stent restenoses after CAS in a tertiary care university hospital and a Veterans Affairs Medical Center. During the last 5 years, 22 carotid arteries (21 patients) underwent CAS. One patient developed thrombosis and rupture of the carotid artery during stenting. Two other patients (3 arteries) developed critical restenosis within 12 months. Subsequent surgical reconstructions included an internal carotid artery (ICA)–to–external carotid artery (ECA) transposition and a common carotid artery (CCA)–to–ICA bypass with reversed saphenous vein (RSV). The patient who underwent CCA–to–ICA bypass later required subclavian–to–ICA bypass because of rapidly progressive intimal hyperplasia and subsequent occlusion of the CCA. The other patient has not had surgical repair because of his deteriorating condition and significant co-morbidities. During the same time period, two additional patients were referred from outside institutions specifically for surgical intervention after carotid stenting. One had delayed rupture of the carotid artery 1 day after stenting and underwent urgent surgical repair. Another patient had early, critical restenosis within the stent and underwent placement of a CCA–to–ICA interposition graft using RSV. Acute treatment failures after CAS can be successfully managed using standard surgical techniques. Patients who develop critical in-stent restenosis requiring surgical repair may need more challenging surgical reconstructions to maintain cerebral perfusion.     

Transvenous copper wire insertion for dural arteriovenous malformations of cavernous sinus

Therapeutic embolization by means of transvenous copper wire insertion was performed in five patients with dural arteriovenous malformations (AVM's) of the cavernous sinus. In each case, angiograms had shown that the AVM's were supplied from both internal and external carotid arteries, which was thought to render complete transarterial embolization difficult. A No. 2.5 French Teflon catheter was introduced into the affected cavernous sinus through the superior ophthalmic or internal jugular vein with the aid of a flexible mini guide wire. Copper wires were pushed by the guide wire into the cavernous sinus until the disappearance or a sufficient decrease in the arteriovenous shunt was noted. The patients' symptoms resolved or improved without any severe complications. Angiography revealed complete disappearance of the lesion immediately after treatment in three cases and follow-up angiography taken within 8 months showed no arteriovenous shunt in any patient. This method is a promising treatment for dural AVM's when conventional transarterial embolization is thought to be difficult.     

A new rat model of chronic cerebral hypoperfusion associated with arteriovenous malformations

OBJECT: A new experimental model of chronic cerebral hypoperfusion was developed to study the effects of systemic arterial shunting and obstruction of the primary vessel that drains intracranial venous blood on cerebral perfusion pressure (CPP), as well as cerebral pathological changes during restoration of normal perfusion pressure. METHODS: Twenty-four Sprague-Dawley rats were randomly assigned to either a sham-operated group, an arteriovenous fistula (AVF) group, or a model group (eight rats each). The animal model was readied by creating a fistula through an end-to-side anastomosis between the right distal external jugular vein (EJV) and the ipsilateral common carotid artery (CCA), followed by ligation of the left vein draining the transverse sinus and bilateral external carotid arteries. Systemic mean arterial pressure (MAP), draining vein pressure (DVP), and CPP were monitored and compared among the three groups preoperatively, immediately postoperatively, and again 90 days later. Following occlusion of the fistula after a 90-day interval, blood-brain barrier (BBB) disruption and water content in the right cortical tissues of the middle cerebral artery territory were confirmed and also quantified with transmission electron microscopy. Formation of a fistula resulted in significant decreases in MAP and CPP, and a significant increase in DVP in the AVF and model groups. Ninety days later, there were still significant increases in DVP and decreases in CPP in the model group compared with the other groups (p < 0.05). Damage to the BBB and brain edema were noted in animals in the model group during restoration of normal perfusion pressure by occlusion of the fistula. Electron microscopy studies revealed cerebral vasogenic edema and/or hemorrhage in various amounts, which correlated with absent astrocytic foot processes surrounding some cerebral capillaries. CONCLUSIONS: The results demonstrated that an end-to-side anastomosis between the distal EJV and CCA can induce a decrease in CPP, whereas a further chronic state of cerebral hypoperfusion may be caused by venous outflow restriction, which is associated with perfusion pressure breakthrough. This animal model conforms to the basic hemodynamic characteristics of human cerebral arteriovenous malformations.     

Retrograde suction decompression of a large internal carotid aneurysm using a balloon guide catheter combined with a blood-returning circuit and STA-MCA bypass: a technical note

It is difficult to treat large internal carotid aneurysms with simple surgical clipping. Here, we present a retrograde suction decompression (RSD) procedure for large internal carotid aneurysms using a balloon guide catheter combined with a blood-returning circuit and a superficial temporal artery to middle cerebral artery (STA-MCA) bypass.All patients underwent an STA-MCA bypass before the temporary occlusion of the internal carotid artery (ICA). A 6-French sheath was inserted into the common carotid artery (CCA), and a 6-French Patrive balloon catheter was placed into the ICA 5 cm past the bifurcation. Aneurysm exposure was obtained; temporary clips were placed on the proximal M1, A1, and posterior communicating (Pcom) segments; and an extension tube was then connected to the balloon catheter. A three-way stopcock was placed, and aspiration was performed through the device to collapse the aneurysm. The aspirated blood was returned to a venous line with an added heparin to prevent anemia after aspiration. During the decompression, the blood flow to the cortical area was supplied through the STA-MCA bypass. After the aneurysm collapse, the surgeon carefully dissected the perforating artery from the aneurysm dome or neck, and permanent clips were then placed on the aneurysm neck. Our procedure has several advantages, such as STA-MCA bypass without external carotid artery occlusion for preventing ischemic complications of the cortical area, anemia may be avoided because of the return of the aspirated blood, and a hybrid operation room is not required to perform this method.     

A successful transcatheter embolization with occluding spring emboli for vertebral arteriovenous fistulas following insertion of Swan-Ganz catheter

Vertebral arteriovenous fistulas caused by insertion of percutaneous monitoring catheter through internal jugular vein are rare complications. This is a case report of a successful treatment by transcatheter embolization using spring occluder for the fistulas. Particular attention should be paid to the following: Normal basilar and contralateral vertebral arteriograms are prerequisites to this procedure in order to avoid its potential neurological hazards. For the complete elimination of the fistulas with retrograde filling, embolic material should be placed in the artery not only proximal but also distal to the fistulas opening.     

Endovascular Treatment of Transverse-Sigmoid Sinus Dural Arteriovenous Malformations Presenting as Pulsatile Tinnitus

Transverse-sigmoid sinus dural arteriovenous malformations (DAVM) are uncommon vascular lesions for which complete cure may be difficult to obtain. A wide variety of treatments for these lesions include observation, arterial compression, surgical resection, and endovascular embolization. We propose that transverse-sigmoid sinus DAVM can be completely cured by occluding the ipsilateral dural sinus with detachable balloon and Guglielmi detachable coils (GDC) coils before arterial feeder embolization with histoacryl. Three patients who presented with pulsatile tinnitus and normal magnetic resonance imaging (MRI) studies underwent angiography, which demonstrated transverse-sigmoid sinus DAVM. All three patients wer treated with retrograde transvenous sinus embolization with complete occlusion of the transverse-sigmoid sinus with detachable balloons and GDC coils with preservation of the vein of Labbé. Subsequently, the various feeders from the external carotid artery were embolized. The tentorial arteries arising from the ipsilateral internal carotid arteries were not embolized in any of the cases, which were still contributing to the DAVM. Complete cure with thrombosis of the tentorial branch of the internal carotid artery (ICA) was seen on follow-up angiogram 1 day after embolization in one patient and on 4-week and 6-week follow-up angiograms in the other two patients. Complete occlusion of the transverse sinus proximal to the vein of Labbé, in spite of incomplete arterial feeder embolization, can result in complete cure of the transversesinus dural AVF if adequate time is given for the remaining feeders to occlude, once the fistula is obliterated.     

Embolization of cerebral aneurysms with a liquid embolus,EVAL mixture: Report of three cases

Summary Embolization of three surgically difficult cerebral aneurysms was performed using our newly developed non-adhesive embolic material, EVAL mixture (ethylene vinyl alcohol copolymer). Conventional embolic materials such as detachable balloons or microcoils were not used because of a large or irregular aneurysmal neck. After temporary occlusion of the parent artery with a superselective balloon catheter, the EVAL mixture was slowly injected through a microcatheter placed in the aneurysm or parent artery. The locations of the aneurysms were anterior communicating artery, basilar artery-posterior cerebral artery and basilar artery-anterior inferior cerebellar artery (BA-AICA). One aneurysmal occlusion and 2 parent artery occlusions were performed. Patients had no persistent deficits. The patient with the BA-AICA aneurysm associated with an arteriovenous malformation died of rupture of the residual AVM due to haemodynamic change 2 weeks after embolization. In selected and limited cases, embolization of surgically difficult cerebral aneurysms using EVAL mixture was more effective and safer than embolization using conventional embolic materials such as balloons and microcoils.