Non-infected carotid artery pseudoaneurysm 29 years after endarterectomy, endovascular management with covered stent.

Pseudoaneurysm formation is a rare complication following carotid endarterectomy (CEA). Arterial pseudoaneurysms lack all three layers of the arterial wall that include the intima, media and adventitia. Pseudoaneurysms are most commonly seen after injuries to the artery in the form of blunt trauma and puncture, and are less common after surgeries such as carotid endarterectomy. These lesions present most frequently as enlarging, pulsatile, expandable masses associated with swelling and pain. Management of this complication is challenging. Traditionally, open surgical repair has been the preferred treatment. Recently, endovascular techniques using stent graft implantation alone or combined graft and coil embolization have offered a less invasive approach for the management of this lesion. Pseudoaneurysm development has been described within hours to several years after initial arterial injury, normally presenting within 5 years. To our knowledge, this is the first case report of pseudoaneurysm formation in a patient presenting 29 years after a carotid endarterectomy; during that time the patient remained completely asymptomatic until 2 months prior to his admission. The patient is an 84-year-old male with a history of stroke which prompted a left carotid endarterectomy in 1981. Twenty-nine years post procedure it was noted that the patient had a lump that was progressively enlarging on the left side of his neck, zone 1. It was pulsatile on examination. MRI/A imaging suggested a left carotid bulb aneurysm. The consulting vascular surgeon felt the patient would not be a good surgical candidate and so stenting was considered. Carotid and cerebral angiogram demonstrated a large 6 cm left carotid pseudoaneurysm off the carotid bulb. The diagnostic procedure was followed by a successful placement of an 8 x 10 cm Viabahn covered stent from the left common carotid artery to the left internal carotid artery. Following the procedure, the carotid artery was patent and there was minimal to no further residual filling of the pseudoaneurysm. Poststenting, the patient remained at his neurological baseline. This case demonstrates that pseudoaneurysm formation can occur as a long term complication after carotid endarterectomy. It may present as a rapidly expandable, pulsatile, vascular lesion in the absence of clinical and sub-clinical infection. Placement of an endovascular stent graft may be a safe and effective option for treatment of infected and non-infected carotid pseudoaneurysm.

Perfusion MR neuroimaging in patients undergoing balloon test occlusion of the internal carotid artery.

BACKGROUND AND PURPOSE: We sought to investigate whether the combination of conventional, diffusion-weighted, and perfusion-weighted MR imaging increases the diagnostic accuracy of balloon test occlusion of the internal carotid artery. We describe perfusion anomalies and patterns of enhancement seen in areas of altered brain perfusion during MR-monitored temporary balloon occlusion of the internal carotid artery. METHODS: Nine patients underwent balloon occlusion testing under standard angiographic conditions with continuous clinical and EEG monitoring. One patient who failed the test by clinical criteria underwent an external carotid to internal carotid bypass operation, followed by a repeat balloon test occlusion, thereby bringing the total number of procedures to 10. Patients were further imaged at 1.5 T with perfusion- and diffusion-weighted imaging as well as with conventional noncontrast and contrast-enhanced turbo fluid-attenuated inversion recovery (FLAIR) and T1-weighted sequences. RESULTS: Seven of 10 patients who tolerated unilateral carotid test occlusion without adverse clinical neurologic or EEG changes exhibited delayed first-pass transit of contrast material through the affected cerebral hemisphere, indicative of altered perfusion without significant concurrent cerebral blood flow or blood volume changes. Four of these patients and both symptomatic patients showed pial or subarachnoid contrast staining in areas of altered perfusion without abnormalities on diffusion-weighted images. CONCLUSION: Our findings indicate that MR perfusion-weighted imaging is safe and easily accomplished in a high-field-strength magnet and that contrast-enhanced turboFLAIR imaging may provide clinically useful MR imaging evidence of abnormal cerebral blood flow and subclinical ischemia.

Outcomes after aneurysm rupture during endovascular coil embolization.

OBJECTIVE: Intracranial aneurysm rupture during placement of Guglielmi detachable coils has been reported, but the management and consequences of this event have not been extensively described. We present our experience with this feared complication and report possible neuroradiological and neurosurgical interventions to improve outcomes. METHODS: We retrospectively reviewed the records for 701 patients with 734 intracranial aneurysms that were treated with endovascular coiling, during a 6-year period, in the metropolitan Minneapolis-St. Paul (Minnesota) area. This analysis revealed 10 cases of perforation during coiling. The management and outcomes were recorded, and the pertinent literature was reviewed. RESULTS: All 10 cases involved previously ruptured aneurysms. This complication occurred sporadically and was not observed in the first 100 cases. Perforation occurred during microcatheterization of the aneurysm in two cases and during coil deposition in eight cases. Seven of the perforated aneurysms were located in the anterior circulation and three in the posterior circulation. Six of the 10 patients made good or fair recoveries; all three patients with posterior circulation lesions died immediately after rehemorrhage. Elevated intracranial pressure (ICP) was noted for all five patients with intraventricular catheters in place. Bilateral pupil dilation and profound hemodynamic changes were noted for eight patients. Coiling was rapidly completed, and total or nearly total occlusion was achieved in all cases. Emergency ventriculostomy was performed to rapidly reduce increased ICP for two patients, both of whom made good recoveries. Hemodynamic and angiographic factors after perforation, such as prolonged systemic hypertension, persistent dye extravasation after deployment of the first Guglielmi detachable coil, and persistent prolongation of contrast dye transit time (suggesting ongoing ICP elevation), were correlated with poor outcomes. CONCLUSION: Previously ruptured aneurysms seem to be more susceptible to endovascular treatment-related perforation than are unruptured lesions. Worse prognoses are associated with iatrogenic rupture during coiling of posterior circulation lesions, compared with those in the anterior circulation. When perforation is recognized, the definitive treatment seems to be reversal of anticoagulation therapy and completion of Guglielmi detachable coil embolization. Immediate neurosurgical intervention is limited in these cases and focuses on decreasing ICP via emergency ventriculostomy. However, these measures may be life-saving, and neurosurgical assistance must be readily available during treatment of these cases.

Pseudomyasthenia resulting from a posterior carotid artery wall aneurysm: a novel presentation: case report.

OBJECTIVE AND IMPORTANCE: Painful oculomotor palsy can result from enlargement or rupture of intracranial aneurysms. The IIIrd cranial nerve dysfunction in this setting, whether partial or complete, is usually fixed or progressive and is sometimes reversible with surgery. We report an unusual oculomotor manifestation of a posterior carotid artery wall aneurysm, which mimicked ocular myasthenia gravis. CLINICAL PRESENTATION: A 47-year-old woman developed painless, intermittent, partial IIIrd cranial nerve palsy. She presented with isolated episodic left-sided ptosis, which initially suggested a metabolic or neuromuscular disorder. However, digital subtraction angiography revealed a left posterior carotid artery wall aneurysm, just proximal to the origin of the posterior communicating artery. INTERVENTION: The aneurysm was successfully clipped via a pterional craniotomy. During surgery, the aneurysm was observed to be compressing the oculomotor nerve. The patient's symptoms resolved after the operation. CONCLUSION: The variability of incomplete IIIrd cranial nerve deficits can present a diagnostic challenge, and the approach for patients with isolated IIIrd cranial nerve palsies remains controversial. Although intracranial aneurysms compressing the oculomotor nerve classically produce fixed or progressive IIIrd cranial nerve palsies with pupillary involvement, anatomic variations may result in atypical presentations. With the exception of patients who present with pupil-sparing but otherwise complete IIIrd cranial nerve palsy, clinicians should always consider an intracranial aneurysm when confronted with even subtle dysfunction of the oculomotor nerve.

Carotid stenting and "extarterectomy" in the management of head and neck cancer involving the internal carotid artery: technical case report.

OBJECTIVE AND IMPORTANCE: Head and neck cancer that invades the internal carotid artery (ICA) represents a significant management challenge. We describe a novel technique that allows for aggressive tumor removal without disrupting blood flow through the affected ICA. CLINICAL PRESENTATION: A 62-year-old man was referred to our institution for management of a neck malignancy involving the ICA. Cerebral angiography suggested that there was good collateral flow from the opposite hemisphere, but the patient reported visual loss in the ipsilateral eye during balloon test occlusion of the ICA. INTERVENTION: A self-expanding stent was deployed in the ICA; it spanned the entire length of the artery involved by tumor. One month later, the patient underwent tumor resection. During surgery, a long ICA arteriotomy was performed directly down to the mesh of the stent. A neoendothelium had formed within the stent, which prevented arterial bleeding. The carotid wall was dissected from the stent without difficulty and removed en bloc with the surrounding tumor. The exposed stent was wrapped circumferentially with a synthetic patch material. The patient tolerated the procedure well, and postoperative angiography demonstrated normal filling of the ICA. CONCLUSION: We describe a novel approach to a patient with head and neck cancer involving the cervical ICA. Preliminary stenting, which allows time for endothelialization before surgery, may permit aggressive tumor resection without interrupting flow through the ICA. This technique obviates the need for complicated carotid reconstruction procedures and avoids the risk of delayed ischemia from carotid sacrifice.

Use of gadolinium as an intraarterial contrast agent in digital subtraction angiography of the cervical carotid arteries and intracranial circulation. Technical note.

Patients with renal insufficiency or other contraindications to iodine-based contrast agents present a significant management dilemma when conventional arteriography is required. The authors describe the use of gadolinium as an alternative contrast agent for arterial digital subtraction (DS) angiography of the cervical carotid arteries (CAs) and intracranial circulation. Three patients with renal insufficiency presented with symptoms of ischemic cerebrovascular disease and inconclusive noninvasive imaging studies, which necessitated conventional angiography. Traditional transfemoral catheterization of the cervical CAs was performed and DS angiographic studies were obtained using gadolinium as an intraarterial contrast agent. In one case, selective arteriographic examination of the internal carotid arteries and vertebrobasilar system was performed as well. High-quality, diagnostic images essentially indistinguishable from routine angiographic studies were obtained in all cases. No patient suffered a complication related to the use of gadolinium, and no patient demonstrated worsened renal function after the procedure. In the setting of a contraindication to iodine-based contrast agents, gadolinium represents an important alternative contrast material that allows for excellent visualization of the cervical CAs and intracranial circulation.

The pathogenesis of arteriovenous malformations: insights provided by a case of multiple arteriovenous malformations developing in relation to a developmental venous anomaly.

OBJECTIVE AND IMPORTANCE: Developmental venous anomalies (DVAs) are common anomalies of intracranial venous drainage that may occur in conjunction with other cerebral vascular malformations. The present case raises important questions regarding the association between anomalous venous drainage patterns and the development of arteriovenous malformations (AVMs). CLINICAL PRESENTATION: We present the case of a 24-year-old man with small AVMs fed by the superior cerebellar artery that drained directly into a large DVA of the cerebellum. INTERVENTION: The patient was managed conservatively and returned 10 years later with recurrent symptoms. A repeat angiogram demonstrated spontaneous thrombosis of the previously documented AVMs; however, new AVMs at a different site that was also fed by the superior cerebellar artery and drained into the same DVA had appeared. The AVMs were completely embolized, and the DVA was left intact. CONCLUSION: Recently, increasing attention has focused on the possible importance of venous outflow disturbance and venous hypertension in the pathogenesis and pathophysiology of AVMs. The potential mechanisms for this association and the implications of the present case are discussed, and the pertinent literature is reviewed.

Intra-aortic balloon counterpulsation augments cerebral blood flow in the patient with cerebral vasospasm: a xenon-enhanced computed tomography study.

OBJECTIVE: We previously established the ability of intra-aortic balloon counterpulsation (IABC) to improve cerebral blood flow (CBF) significantly in a canine model of cerebral vasospasm. This study was performed to assess the efficacy of IABC in a patient with cardiac dysfunction and severe cerebral vasospasm that was refractory to traditional treatment measures. METHODS: We report our experience with the clinical use of IABC to treat cerebral vasospasm in a patient who suffered subarachnoid hemorrhage and concomitant myocardial infarction. Hypertensive, hypervolemic, hemodilution therapy was ineffective, and IABC was instituted. Xenon-enhanced computed tomography (Xe-CT) was utilized to obtain serial measurements of CBF with and without IABC over a 4-day period. RESULTS: IABC dramatically improved cardiac function in this patient, and Xe-CT demonstrated significant improvement in CBF with IABC. The average global CBF was 20.5 +/- 4.4 ml/100g/min before versus 34.7 +/- 3.8 ml/100g/min after IABC (p < 0.0001, paired student's t-test). The lower the CBF before IABC, the greater the improvement with IABC (correlation coefficient r = 0.83, p = 0.0007). CBF improvement ranged from 33% to 161% above baseline, average 69.3%. No complications of IABC were observed. CONCLUSIONS: This is the first report demonstrating the ability of IABC to improve CBF in a patient with vasospasm. We suggest that IABC is a rational treatment option in select patients with refractory cerebral vasospasm who do not respond to traditional treatment measures.

Functional magnetic resonance imaging as a management tool for cerebral arteriovenous malformations.

The location of eloquent cortex, such as the motor strip, the visual cortex, or Broca's area, may be difficult to predict even with multiprojectional magnetic resonance imaging (MRI). Distortion and displacement of this cortex may occur with a congenital lesion, such as an arteriovenous malformation, or by an acquired disease, such as a neoplasm. A desire to avoid damaging these eloquent areas by conventional surgery, radiosurgery, or endovascular surgery makes their accurate identification an important part of the pretherapeutic planning process. Blood oxygen level dependent functional MRI is a technique that uses the local increase of oxyhemoglobin concentration in the patient that occurs as a result of the increase in flow rate and blood volume in eloquent cortex undergoing stimulation from, for example, flashing lights, hand movements, or speech. We have used the blood oxygen level dependent technique to localize eloquent cortex relative to arteriovenous malformations and tumors. Using a 4.0-T magnetic resonance (MR) system, there is a sufficiently high degree of spatial resolution of the MR signal intensity changes during stimulation to allow the identification of eloquent cortex. Alternative, non-MR, invasive techniques for functional localization include electrocorticography and stimulation from subdural grids and strips. Noninvasive, non-MR technologies, such as positron emission tomography and magnetoencephalography, can also provide functional localization of eloquent cortex. However, the perfection of functional MRI at the 1.5-T field strength and the large number of such MR systems in operation mean that a highly accurate cerebral cortical localization technique can be available to most neuroscientists without the need to purchase alternative expensive technology.

Intra-aortic balloon counterpulsation augments cerebral blood flow in a canine model of subarachnoid hemorrhage-induced cerebral vasospasm.

We tested the effect of intra-aortic balloon counterpulsation (IABC) on cerebral blood flow (CBF) in a canine model of cerebral vasospasm. Cerebral vasospasm was induced in ten adult mongrel dogs using a "two-hemorrhage" model. CBF was then measured using radiolabeled microspheres, before and after activation of an intra-aortic balloon pump. Physiologic parameters including pCO2 and cardiac filling pressures were maintained constant during the experiment. Cardiac output was monitored in each animal. CBF increased with IABC in all ten animals. The mean CBF was 78.5 milliliters per 100 grams per minute (ml/100g/min) before versus 93.3ml/100g/min after IABC (P = 0.0001). Increases in CBF were associated in most, but not all, cases with increases in cardiac output. This study supports the ability of IABC to raise CBF in the setting of cerebral vasospasm. IABC may represent an important clinical option in cases of refractory vasospasm following aneurysmal subarachnoid hemorrhage.

Radiologic diagnosis and staging of head and neck squamous cell carcinoma.

The predominant extracranial head and neck cancer in adults is squamous cell carcinoma. The purpose of this article is to discuss the radiographic evaluation of these patients with computed tomography (CT) or magnetic resonance (MR) imaging prior to therapeutic intervention. Specific focus is given to the efficacy of CT and MR imaging, as an adjunct to clinical staging, for evaluation of the primary tumor, and metastatic adenopathy. MR imaging, because of its improved soft tissue contrast and multiplanar capability, is probably superior to CT for evaluation of the primary tumor in patients with squamous cell carcinoma. CT, however, remains the gold standard for identifying metastatic adenopathy and in most institutions remains the study of choice for evaluating this patient population.

Radiologic diagnosis, staging, and follow-up of adult central nervous system primary malignant glioma.

Glioma represents the most common primary intra-axial brain tumor. Currently, magnetic resonance (MR) imaging is the study of choice for the radiographic evaluation of patients with primary central nervous system glioma prior to and following therapeutic intervention. Computed tomography and MR imaging are frequently used for stereotactic biopsy and mapping. MR spectroscopy and/or thallium-201 single photon emission computed tomography may prove helpful in differentiating recurrent malignancy from radiation-induced necrosis.

In vitro evaluation of caval filters.

This experiment demonstrated the clottrapping ability of two commercially available filters, the Mobin-Uddin and Greenfield, and three experimental filters developed by Amplatz, Günther, and Gianturco. Each filter was tested in a polyethylene tube simulating the inferior vena cava. Separate series of 10 clots, each 3 cm long and 6 mm or 9.2 mm in diameter, were exposed to the test filter. The Mobin-Uddin and Amplatz filters failed by overload: acutely elevated pressures forced clots outside the skirt of the former, and between the limbs of the latter. The Günther filter trapped all incident clots, but migrated downstream when occluded by clot. The Greenfield filter passed clots at normal pressures between its widely spaced legs. The Gianturco (bird's nest) passed clots at normal pressures as well. While filters performed suboptimally, strengthening the anchoring struts of the Günther filter would result in a secure, effective filter.

The addition of tobramycin to contrast bone cement. Effect on flexural strength.

Samples of polymethylmethacrylate (PMMA) bone cement were polymerized in vitro with no additives and with the following additives: methylene blue dye, tobramycin, methylene blue plus tobramycin. After storage for 7 days in saline, samples were tested to failure in three-point bending. Addition of the antibiotic significantly weakened the cement (to 87% of control). However, the combination of tobramycin plus methylene blue was no weaker than tobramycin alone, suggesting that addition of both dye and antibiotic to bone cement is probably a reasonable clinical practice.