Emergency EC-IC bypass for symptomatic atherosclerotic ischemic stroke

Previous studies have shown that extracranial–intracranial (EC-IC) bypass surgery has no preventive effect on subsequent ipsilateral ischemic stroke in patients with symptomatic atherosclerotic internal carotid occlusion and hemodynamic cerebral ischemia. A few studies have assessed whether an urgent EC-IC bypass surgery is an effective treatment for main trunk stenosis or occlusion in acute stage. The authors retrospectively reviewed 58 consecutive patients who underwent urgent EC-IC bypass for symptomatic internal carotid artery or the middle cerebral artery stenosis or occlusion between January 2003 and December 2011. Clinical characteristics and neuroimagings were evaluated and analyzed. Based on preoperative angiogram, responsible lesions were the internal carotid artery in 19 (32.8 %) patients and the middle cerebral artery in 39 (67.2 %). No hemorrhagic complication occurred. Sixty-nine percent of patients showed improvement of neurological function after surgery, and 74.1 % of patients had favorable outcome. Unfavorable outcome was associated with insufficient collateral flow and new infarction after bypass surgery.     

Current trends in neovascular glaucoma treatment

Neovascular glaucoma is divided in three clinical stages: rubeosis iridis, secondary open-angle glaucoma, and synechia of the angle-closure glaucoma. 36% of neovascular glaucomas occurs after central retinal vein occlusion, 32% after diabetic proliferative retinopathy, and 13% occurs after carotid artery obstructive. The key of success in the treatment of neovascular glaucoma is the early and rightly diagnosis, the treatment is aimed mainly at relieving pain, as the prognosis for maintaining visual function is extremely poor. The most important surgical procedures are trabeculectomy, artificial drainage shunts and cyclo-distraction by trans-scleral diode laser. This essay presents a synthesis of modern principle data concerning neovascular glaucoma.     

Cerebrovascular CO2 reactivity after carotid artery occlusion

Cerebral blood flow (CBF) was measured in 39 men at normocapnia and after 5% CO2 inhalation using the xenon-133 technique. Twenty-three patients had unilateral carotid artery occlusion with no angiographic evidence of contralateral carotid artery stenosis or ophthalmic collateral flow. Eleven of these patients had undergone extracranial-intracranial (EC-IC) bypass surgery. Sixteen age-matched normal men underwent CBF measurements at normocapnia and hypercapnia to provide control data. Mean hemispheric CBF was not different between hemispheres ipsilateral and contralateral to the carotid artery occlusion either in the patients who had undergone bypass surgery or in those with carotid artery occlusion alone. Considering all patients with carotid artery occlusion, mean CO2 reactivity was decreased in the hemisphere ipsilateral to the occlusion as compared to the contralateral hemisphere in both groups. Based on data from normal individuals, a hemispheric difference in CO2 reactivity of more than 0.94%/mm Hg PaCO2 or a global CO2 reactivity of less than 0.66%/mm Hg PaCO2 was considered abnormal for an individual patient. Six of 23 patients with carotid artery occlusion (three with an EC-IC bypass) had global or hemispheric abnormalities in CO2 reactivity. Patients with impaired CO2 reactivity were not distinguishable from other patients by neurological examination, presence of transient ischemic attacks, or evidence of infarction on computerized tomography scanning. This test was safe and simple to perform and may be a useful means of detecting impaired cerebrovascular collateral reserve capacity. If impaired CO2 reactivity after carotid artery occlusion proves to be associated with a high risk of subsequent stroke, the test would provide a physiological basis for selecting a subgroup of patients who could be helped by cerebral revascularization.     

Hemodynamic compensation via an excimer laser-assisted, high-flow bypass before and after therapeutic occlusion of the internal carotid artery

OBJECTIVE: High-flow, extracranial-intracranial (EC-IC) bypass operations are performed to prevent strokes among patients with giant aneurysms who cannot tolerate internal carotid artery (ICA) occlusion. However, the volume flow through the bypass, compared with preoperative ICA flow, has not been evaluated for any type of bypass. We describe a prospective case study that tested the ability of the high-flow EC-IC bypass to replace the volume flow of the ipsilateral ICA after deliberate ICA occlusion. METHODS: Seven consecutive patients with giant aneurysms of the ICA who experienced test occlusion failure underwent nonocclusive, excimer laser-assisted, EC-IC bypass surgery before permanent ICA occlusion. Volume flow values in the ICAs, the basilar artery, the EC-IC bypass, and the middle cerebral arteries were measured with magnetic resonance angiography. RESULTS: No significant changes in volume flow to the ipsilateral and contralateral hemispheres were observed after bypass surgery and therapeutic ICA occlusion. Before bypass surgery, the volume flow through the ipsilateral ICA was 243 +/- 74 ml/min, that through the contralateral ICA was 264 +/- 32 ml/min, and that through the basilar artery was 141 +/- 43 ml/min. After bypass surgery and therapeutic occlusion of the ipsilateral ICA, the volume flow through the bypass was 199 +/- 72 ml/min, that through the contralateral ICA was 303 +/- 82 ml/min, and that through the basilar artery was 153 +/- 72 ml/min. No significant preoperative versus postoperative changes in middle cerebral artery flow were observed on either side. CONCLUSION: The flow through the high-flow EC-IC bypass was able to replace the volume flow of the ipsilateral ICA after deliberate ICA occlusion for the treatment of giant aneurysms.     

Long-term evaluation of EC-IC bypass patency

Summary The EC-IC Bypass Study Group could not detect any benefit from surgery compared to medical management in the prevention of stroke in 1985 [15]. During the past years surgical revascularization was re-evaluated and considered as an appropriate treatment for a small subgroup of patients with recurrent focal cerebral ischaemia and impaired haemodynamics. This retrospective study examines the long-term benefit and patency rate of bypass.We present a follow-up of 5.6 years of 47 patients, all of whom underwent byupass surgery after 1985. Forty patients suffered recurring transient ischaemic attacks due to uni- or bilateral internal carotid artery occlusion. Examination included neurologic status, TCD with CO₂ or Diamox challenge, angiography, CT and SPECT scans.Neurological improvement was seen in 23% of patients with better results after early surgery, a worsening in 22% suffering further ischaemic events on a postoperative average of 2.8 years. Patency rate for vein graft material was 50%, for the STA-MCA procedure 91%. Occlusion of the vein graft occurred on an average after 1.4 years, other anastomosis after 2.7 years.We conclude that only few patients derived long-term benefit from EC-IC bypasses. Functioning of the bypass worsens over time, suggesting a role for surgery predominantly in the first year of ischaemic events due to insufficient collateral supply. Actual indications for bypass surgery may be patients with failure of maximal medical therapy and progressive ischaemia and haemodynamic compromise.     

Cerebral revascularization for ischemic disease in the 21st century

Shortly after the first extracranial to intracranial (EC-IC) carotid artery bypass was performed by Yasargil in 1967 for internal carotid artery occlusion, cerebral revascularization became widely accepted in the neurosurgical field, and the procedures became increasingly used as practitioners began to master the technical aspects of the surgery. The procedures were performed for intracranial arterial stenosis and occlusion and used as an adjunct in the treatment of large aneurysms and skull base tumors. The results of the EC-IC bypass group trial in 1985 were surprising to many and sobering to all; EC-IC bypass for stenosis or occlusion of the high internal carotid artery or middle cerebral artery did not decrease the risk of subsequent stroke compared with medical management. Rather, the incidence of stroke increased, and the events were noted to occur sooner than with medical therapy alone. Despite the known limitations of this landmark study, the number of EC-IC bypass procedures fell precipitously over the ensuing decades. Despite this significant setback, cerebral revascularization is not obsolete. This article revisits the sequence of events leading to the rise of revascularization surgery and recaps the impact of the EC-IC bypass trial. The limitations of the trial are discussed, as are current studies evaluating the efficacy of cerebrovascular bypass procedures for symptomatic carotid occlusive disease. The authors review the accepted indications for bypass surgery in the early 21st century.     

Endarterectomy for narrowing of the external carotid artery in a patient who underwent extracranial-intracranial bypass for occlusion of the internal carotid artery--case report

A 56-year-old man had undergone extracranial-intracranial (EC-IC) bypass surgery for occlusion of the right internal carotid artery. Six years later, he complained of transient episodes of numbness in the left arm, occurring periodically over the previous 3 months. Neuroimaging showed the right external carotid artery was severely narrowed and cerebral blood flow (CBF) was diffusely low. Endarterectomy of the right external carotid artery was performed. Postoperative CBF was markedly improved, suggesting that EC-IC bypass became effective again by endarterectomy of a parent artery.     

Rupture of a giant carotid aneurysm after extracranial-to-intracranial bypass surgery

We report a case of a fatal rupture of a previously unruptured giant aneurysm of the bifurcation of the internal carotid artery (ICA), which occurred after an extracranial-intracranial (EC-IC) bypass and the partial occlusion of the ICA. Interim angiography showed retrograde filling of the proximal middle cerebral artery to the aneurysm. There have been four previously reported cases of giant aneurysms rupturing after treatment with an EC-IC bypass and carotid ligation, and it appears likely that a change in pressure/flow dynamics produced by the bypass may have been the cause. The technique of carotid ligation with an EC-IC bypass is used frequently to treat unclippable intracranial aneurysms, and the resulting hemodynamic changes need to be considered carefully to prevent this type of complication. To minimize hemodynamic stress on the aneurysm, we suggest that 1) the bypass caliber should be as small as possible consistent with sufficient cerebral blood flow after ICA occlusion, and 2) complete ICA occlusion should be performed as soon as possible after the bypass.     

Management of giant intracranial ICA aneurysms with combined extracranial-intracranial anastomosis and endovascular occlusion

Nine patients with giant internal carotid artery (ICA) aneurysms (greater than 2.5 cm in diameter) were subjected to a combined extracranial-intracranial (EC-IC) bypass procedure and endovascular ICA occlusion during 1987 and 1988. The procedures were performed under one anesthetic. In all cases the collateral circulation had been judged insufficient on the basis of a strict preoperative testing protocol including: cerebral panangiography, electroencephalography, somatosensory potential recording, and cerebral blood flow monitoring during manual compression of the ICA in the neck. There were four intracavernous ICA aneurysms, four carotid-ophthalmic artery aneurysms, and one supraclinoid ICA aneurysm. All patients showed symptoms and signs of compression of the surrounding nervous structures. In the five cases of intradural lesions, the artery was occluded at the level of the aneurysm neck, so the ophthalmic artery had to be occluded. There was, nevertheless, no case of worsening of vision following surgery, and all nine patients showed significant improvement following the combined procedure. A combined EC-IC bypass procedure and endovascular ICA occlusion allows for immediate verification of the surgical results and appears to be a worthwhile method for treating giant intracranial aneurysms.     

Ophthalmologic findings as predictors of carotid artery disease

Vascular events that occur in the brain also occur in the eye, giving rise to different ophthalmologic manifestations that range from amaurosis fugax to complete blindness due to central retinal artery occlusion. The objective of this study was to ascertain the relative frequency and predictive value of ocular findings suggestive of carotid occlusive disease in patients being investigated for carotid endarterectomy. The charts of 366 patients undergoing carotid angiography for evaluation of cerebrovascular or visual symptoms over a 5-year period were reviewed. The presence of eye symptoms, neurologic symptoms, cervical bruits, and ophthalmologic findings on admission was recorded and correlated with the presence of significant carotid artery stenosis (>or=50%). Positive eye findings included retinal plaques, rubeosis iridis, neovascular glaucoma, venous stasis retinopathy, central and branch retinal artery occlusion, ischemic optic neuropathy, and asymmetric hypertensive retinopathy. Seventy-five patients (21%) presented with amaurosis fugax; 41 patients (11%) were found to have one or more ocular findings consistent with carotid artery disease. All patients with positive eye findings were diagnosed by ophthalmologists, who were consulted in 94 cases. Of these 41 patients, 29 (70.3%) were subsequently shown to have greater than 50% stenosis of the common or internal carotid artery. Ten patients had amaurosis fugax, a carotid bruit, and positive eye findings. All were shown to have a significant carotid stenosis. This study shows that ocular pathology, if diagnosed, is correlated with carotid stenosis, especially if other contributing history and physical findings are also considered.     

Superficial temporal artery-middle cerebral artery anastomosis in a patient of temporal arteritis with internal carotid artery occlusion: a case report

Temporal arteritis is a rare systemic autoimmune disease and the arteritic process in this case of temporal arteritis involved large and medium-size arteries. Temporal arteritis with internal carotid artery (ICA) occlusion is very rare. We report a case of temporal arteritis with ICA occlusion following superficial temporal artery (STA) -middle cerebral artery (MCA) anastomosis, together with steroid therapy. A 73-year-old female presented with a headache, visual disturbance of left side, and suppression of activity. Left STA was inflammatory and overswelling. Magnetic resonance angiography (MRA) and angiography revealed occlusion of the left internal carotid artery (ICA) at the cervical portion and lowering of vascular reserve on PAO SPECT. Diagnosis as temporal arteritis was conclusive due to the clinical presentation, laboratory studies, and left temporal artery biopsy, so steroid pulse therapy was initiated. Inflammation of left STA disappeared after steroid therapy, but left ICA occlusion on angiography and lowering of vascular reserve on SPECT remained for 3 months afterwards. Because of this, STA-MCA anastomosis was performed. There were no complications after the operation and the donor artery has been patent for two years. Temporal arteritis with ICA occlusion that requires extracranial-intracranial bypass (EC-IC bypass) is very rare. STA-MCA anastomosis with steroid therapy is effective for the prevention of cerebral infarction.     

The ELANA technique: Constructing a high flow bypass using a non-occlusive anastomosis on the ICA and a conventional anastomosis on the SCA in the treatment of a fusiform giant basilar trunk aneurysm

Summary A patient with a partially thrombosed fusiform giant basilar trunk aneurysm presented with devastating headache and symptoms of progressive brain stem compression. Having an aneurysm inaccessible for endovascular treatment, and after failing a vertebral artery balloon occlusion test, he was offered bypass surgery in order to exclude the aneurysm from the cerebral circulation and relieve his symptoms. A connection between the intracranial internal carotid artery and the superior cerebellar artery was created whereupon the basilar artery was ligated just distally to the aneurysm. The proximal anastomosis on the internal carotid artery was made using the excimer laser-assisted non-occlusive anastomosis (ELANA) technique, while a conventional end-to-side anastomosis was used for the distal anastomosis on the superior cerebellar artery. Intra-operative flowmetry showed a flow through the bypass of 40ml/min after ligation of the basilar artery. An angiogram 24 hours later showed normal filling of the bypass and the vessels supplied by it, but also disclosed a subtotal occlusion of the proximal ipsilateral middle cerebral artery with delayed filling distally. The patient, who had a known thrombogenic coagulopathy, died the following day. Autopsy showed no signs of ischemia in the territories supplied by the bypass, but a thrombus in the proximal middle cerebral artery and massive acute hemorrhagic infarction with swelling in its territory and uncal herniation. Multiple fresh thrombi were found in the lungs. The ELANA anastomosis showed re-endothelialisation without thrombus formation on the inside.     

Surgical treatment for paediatric patients with moyamoya disease by indirect revascularization procedures (EDAS,EMS, EMAS)

Surgical results of paediatric patients with Moyamoya disease who were treated by indirect revascularization procedures are reported. Encephalo-duro-arterio-synangiosis (EDAS), encephalomyo-arterio-synangiosis (EMAS), and/or encephalo-myo-synangiosis (EMS) were performed on 47 sides of 29 children with Moyamoya disease. The results of those non-anastomotic EC-IC bypass procedures were evaluated clinically, angiographically, and by computed tomography (CT). Postoperative external carotid angiograms showed a good collateral formation through EDAS, EMAS, or EMS in about 70-80 percent of all surgically treated sides. The symptoms such as TIA, RIND, and/or involuntary movements disappeared in the cases with a good collateral formation but not in those with insufficient development of the collateral circulation. The indirect EC-IC bypass surgery seems effective for most of the children with Moyamoya disease who present with ischaemic signs.     

Bypass surgery using a radial artery graft for bilateral extracranial carotid arteries occlusion

A patient presenting with recurrent ischemic attacks was demonstrated to have complete occlusion of the right common and left internal carotid arteries. An external carotid angiogram showed a large left superficial temporal artery (STA) supplying both sides of the scalp. ¹²³I-IMP single photon emission computed tomography (SPECT) revealed hypoperfusion of the both hemispheres, especially the left cerebral hemisphere. An extracranial-intracranial (EC-IC) bypass was performed using a radial artery graft interpositioned between the proximal part of the STA and the M2 segment, thus preserving blood flow to the scalp through the STA. Postoperative angiography after 1 year showed good circulation through the anastomosis, and ¹²³I-IMP SPECT studies demonstrated increased cerebral perfusion. The patient improved clinically. The surgical technique is described below. Received: 2 June 1998 / Accepted: 15 April 1999     

Effects of EC-IC bypass surgery on cognitive impairment in patients with hemodynamic cerebral ischemia

BACKGROUND: Chronic ischemia because of internal carotid artery (ICA) occlusive disease may result in dementia. The goal of this study was to assess cognitive impairment in symptomatic patients with hemodynamic cerebral ischemia and determine the efficacy of extracranial-intracranial (EC-IC) bypass in restoring neuropsychologic integrity. METHODS: Twenty-five patients were defined by clinical and neuroradiological criteria as suffering from hemodynamic cerebral ischemia because of unilateral ICA or middle cerebral artery occlusion. Subjects underwent assessment of cerebral blood flow and metabolism using positron emission tomography (PET) before and after bypass surgery. To provide data regarding cognition, changes in the Japanese Wechsler Adult Intelligence Scale Revised (WAIS-R) were recorded. RESULTS: Preoperative study of patients revealed significant impairment in cerebral blood flow and metabolism as well as reduced WAIS-R score. Among the factors considered, only elevated regional oxygen extraction fraction and reduced regional cerebral metabolic rates of oxygen were significantly associated with preoperative cognitive impairment (p = 0.0032 and p = 0.0255, respectively; logistic regression analysis). After bypass surgery, cerebral blood flow and metabolism improved significantly, and the WAIS-R score increased. CONCLUSIONS: Symptomatic patients with hemodynamic cerebral ischemia displayed impaired cognition that was partially alleviated with EC-IC bypass surgery.     

Flow quantification of the non-occlusive excimer laser-assisted EC-IC bypass

Summary  Background. For six years, we used the Excimer laser-assisted nonocclusive anastomosis technique for high-flow revascularization of the brain in patients with either nonclippable and noncoilable giant aneurysms of the internal carotid or basilar artery or progressive stroke associated with occlusive disease of the internal carotid artery. The aim of this study is to assess the blood flow capacity of this type of Extra-Intracranial bypass and its haemodynamic behaviour over time.  Methods. Twenty-six patients with a giant aneurysms and 8 patients with occlusive disease of the internal carotid artery were treated with the nonocclusive Excimer laser assisted EC-IC bypass. intra-operatively, direct measurements of flow in the EC-IC bypass were performed in all patients (Transonic Systems, Inc., Ithaca, NY). Postoperatively, follow up measurements of flow were performed with MR angiography in 14 patients with a giant aneurysm after occluding the internal carotid artery, and 7 patients with occlusive carotid disease.  Results. The mean flow in the laser assisted bypasses in the group of patients with a giant aneurysm was 158 ml/min after ligation or balloon oclusion of the ICA. The mean flow of the laser assisted bypass in the group of patients with ICA occlusive disease was 130 ml/min. A comparison with data on flow capacity of conventional EC IC bypasses is made. A demonstrated increase of flow in the bypass during follow up is discussed from a haemodynamic point of view.  Conclusions. The results of this study demonstrate that the flow capacity of the nonoccluding excimer laser assisted bypass is much higher than the capacity of the conventional, more peripherally located conventional EC IC bypass, and should therefore be denoted as High-Flow EC IC bypass. Consequently, this type of bypass can be a powerful and safe tool in new revascularization strategies.     

Late spontaneous recanalization of a symptomatically occluded internal carotid artery two years after extra-intracranial bypass. Case report and review of the literature

Spontaneous recanalization of the internal carotid artery (ICA) is rarely observed. Mainly case reports are published. Most often early recanalization occurs within days or weeks and only a few cases of late recanalization months or years after detected occlusion are reported. Symptomatic bilateral ICA occlusion is regarded as an acceptable indication for extra-intracranial (EC-IC) bypass. The authors report on a case with bilateral symptomatic ICA occlusion and EC-IC bypass >2 years prior to detected spontaneous leftsided recanalization. Spontaneous recanalization unmasking a high degree ICA stenosis at the carotid bifurcation allowed a successful subsequent surgical recanalization in this patients. Mechanisms of early and late recanalization as well as treatment options are discussed.     

EC-IC bypass surgery using a long vein graft--reconstructive procedures for the occluded long vein grafts

EC-IC bypass using a long vein graft has an advantage creating a large amount of blood flow immediately after the anastomosis, but on the other hand, disadvantage of relatively frequent incidence of the vein graft occlusion. In this report, we present three kinds of reconstructive operative procedures for the stenotic or occluded long vein grafts. Type A: A long vein graft bypass between external carotid and posterior cerebral artery was found occluded intraoperatively by the thrombosis occurred where the vein graft was injured during harvesting. Reconstruction was made simply by resecting the occluded segment of the graft and end-to-end suturing. Type B: A long vein graft used in subclavian artery-middle cerebral artery bypass was occluded three days postoperatively at the supraclavicular fossa by bleeding from the anastomosis site. The vein graft was found compressed and thrombosed. We reconstructed the occluded bypass by resecting the occluded supraclavicular segment and interposing a short vein graft with end-to-end anastomosis. Then, thrombectomy of the remaining vein graft was followed. Type C: A long vein graft used in external carotid-middle cerebral artery bypass stenosed at the anastomosis site with the external carotid artery a day after the operation. The stenotic bypass was successfully reconstructed by bridging a new short vein graft from another portion of the external carotid artery on the long vein graft distal to the stenotic site. All the long vein grafts we have done reconstructive surgery have been working well one to four years follow-up periods. So, we conclude that whenever a long vein graft occludes it should be reconstructed promptly before the vein graft becomes necrotic.     

First clinical experience with excimer assisted high flow bypass surgery of the brain

Summary A new type of revascularization of the brain is used in patients with brain ischaemia, caused by an occlusion of one or both internal carotid arteries, and in patients in whom the internal carotid artery has been deliberately occluded for the treatment of a giant aneurysm of the internal carotid artery.A so-called high flow extra-intracranial bypass operation is performed. An arterial or venous transplant is interposed between a branch of the external carotid artery or the external carotid artery itself and the intracranial portion of the internal carotid artery. The anastomosis with the intracranial portion of the internal carotid artery is made without temporary occlusion of the recipient artery and with the aid of the newly developed Excimer laser assisted anastomosis technique.The results of animal experiments and of a clinical series of 9 patients are reported.     

Tailored flow alteration treatment for intracranial internal carotid artery aneurysms: strategy beyond parent artery occlusion with bypass. Case report

A 58-year-old woman with multiple right internal carotid artery (ICA) aneurysms detected incidentally was referred to us. Three-dimensional computed tomography (CT) angiography revealed a broad-necked paraclinoid aneurysm and an aneurysm on the C(1) segment. Aneurysm clipping with preservation of the anterior choroidal artery and posterior communicating artery was not possible because these vessels could not be adequately identified. Intraoperative digital subtraction angiography during obliteration of the cervical portion of the ICA confirmed retrograde flow from the extracranial-intracranial (EC-IC) bypass to the right ophthalmic artery and stagnation of flow in the aneurysms. The cervical portion of the ICA was ligated. Postoperative three-dimensional CT angiography confirmed complete occlusion of both aneurysms and absence of ischemic lesions involving branches of the ICA. Reversal of the blood flow in the ICA via the EC-IC bypass primarily into the ophthalmic artery as the flow outlet by obliterating the cervical portion of the ICA was successful. To prevent ischemia in the territory fed by the perforating arteries of the ICA, tailored flow alteration treatment may be superior to simple parent artery occlusion of the ICA with/without bypass. The pattern of flow alteration should be deliberately based on individual anatomic variations, especially the preservation of flow outlets.