Spontaneous Arteriovenous Fistula of the Vertebral Artery

Three cases of spontaneous arteriovenous fistulas of the vertebral artery (VAF) are reported. In one case the only symptom was a cervical bruit; in the other two cases, symptoms of multiple cervical radiculopathy were also observed. Definitive diagnostic findings were obtained by Doppler ultrasonography, computed tomography, magnetic resonance imaging, and angiography. Clinical signs of radiculopathy disappeared after endovascular balloon occlusion of the fistula, in about 1 month. In one case the vertebral artery was occluded without clinical consequences.

High-resolution, three-dimensional, and contrast-enhanced ultrasonographic findings in diseases of the eye()

OBJECTIVES

To review the contrast-enhanced ultrasound (CEUS) and 3D ultrasound findings (3D-US) in various pathologies involving the eye and orbit and to compare them with high-resolution US (HRUS) findings.

BACKGROUND

CEUS is a valid diagnostic tool for study several districts. There are numerous pathological conditions of the eye in which CEUS can be very helpful or detrimental. IMAGE FINDINGS: We review a wide range of ocular lesions, traumatic (retinal and choroidal detachments) and malignant (choroidal melanoma, tumors inside and outside the muscle cone) evaluated alternatively with CEUS and 3D and compare these findings with those obtained with HRUS. Dysthyroid orbitopathy is not included in this review.

CONCLUSION

CEUS plays a central role in the differentiation of detached retina (vascular) and vitreous membranes (avascular). It is also helpful in the assessment of tumor of the eye, in planning treatment for choroidal melanoma, and in assessing orbital masses for neovascularization. HRUS is highly effective in the detection of traumatic and non-traumatic lesions of the eye, but it is less effective for the assessment of orbital lesions. The 3D module has increased the diagnostic value of CEUS. CEUS is cost-effective and can be used when CT and MR cannot be performed.

Rebleeding and ischemia after acute endovascular treatment of ruptured dissecting subarachnoid vertebral artery aneurysms

SUMMARY

Dissection aneurysms of the vertebral artery represent 3.2% of all cerebral aneurysms and 28% of intracranial dissection aneurysms. Dissection of the vertebral artery in its intracranial segment (V4) usually causes a subarachnoid hemorrhage (SAH) from subadventiatial extension of the vessel wall hematoma. Rarely (one case in seven), the symptomatology is characterized by brain stem ischemia from the vertebral artery and/or postero-inferior cerebellar artery occlusive dissection. The high rebleeding (18-33% with a 10+/-5 day interval between the first and the second bleeding) and mortality (> 45%) rates 1, 13 of this disease prompt emergency treatment usually consisting in endovascular coiling of the dissection aneurysm and/or the dissected segment of the parent vessel. Herein we report our experience in endovascular coiling of acutely ruptured dissecting aneurysms of the vertebral artery dissection in V4 segment. We focus the discussion on the risk of rebleeding and the ischemic complications that my occur after endovascular or surgical treatment.

Intra-arterial thrombolysis in basilar artery occlusion and recent haemorrhagic stroke due to arteriovenous malformation

We report the case of a young patient suffering from a severe ischaemic stroke due to basilar artery occlusion occurring during selective digital subtraction angiography. This examination was performed in order to assess an arteriovenous malformation in posterior cerebral artery territory responsible for haemorrhagic stroke occurring 17 days before. Intra-arterial thrombolysis with urokinase was performed and basilar artery recanalization was obtained 8 h after stroke onset. Despite the severe neurological impairment, the prolonged symptoms of ischaemia and the high bleeding risk due to the recent cerebral haemorrhage in the same vascular territory involved in thrombolysis, the treatment determined a very favourable clinical outcome.

Meningioma-associated brain oedema: the role of angiogenic factors and pial blood supply

BACKGROUND

Approximately 60% of meningiomas are associated with perilesional brain oedema. Several aspects have been evaluated in order to understand the pathophysiological mechanisms of oedema (age, sex of the patient, size and location of the tumour, histotype, grading), although at present they have yet to be completely clarified. We focused on pial blood supply, microvascular density (MVD) and angiogenic growth factors (i.e. vascular endothelial growth factor--VEGF) in order to evaluate their putative role in the development of brain oedema.

METHODS

We retrospectively studied 55 patients with intracranial meningiomas. Computerized tomography (CT) and angiographic studies were obtained in all cases. The angiograms provided an accurate differentiation between pial and dural blood supply, concomitantly with its semi-quantitative evaluation. The location and the volume of oedema, in relation to the meningioma surface, was evaluated using CT scans, as an oedema index (E/I). We also determined the expression of VEGF and MVD using standard immunohistochemical methods.

RESULTS

Thirty-two out of 55 meningiomas presented peritumoural oedema, with an angiographic blush ranging from 2 to 4; VEGF protein was expressed in 27 out of 32 cases, independent of grade or histotype of tumours. In all patients, MVD ranged from 4 to 33.3 vessels (median value: 10.6). A significant relationship was found between the expression of VEGF and MVD (p = 0.0003) and between VEGF and E/I (p = 0.0023). Moreover, the E/I ratio was related to the blush (p = 0.0005). A significant association was also present between VEGF expression and pial blush (p = 0.0001).

CONCLUSION

Our data confirm the central role of VEGF and pial blood supply in the pathogenesis of peritumoural oedema and support the hypothesis that the development of oedema in meningioma is vasogenic in type.

Early thrombolysis in stroke due to basilar artery occlusion

Basilar artery occlusion is usually associated with a poor prognosis. Nevertheless, intra-arterial thrombolysis has been shown to improve clinical outcome in selected cases. We report the case of a 29-year-old patient who suffered a severe ischemic stroke due to basilar artery occlusion and who was treated with intra-arterial thrombolysis within 3 h of symptoms onset; treatment was followed by an almost full functional recovery. The young age of the patient, short segment occlusion in the middle tract of the artery, good collateral supply, and early recanalization may account for the favorable prognosis.

Role of electrothrombosis in aneurysm treatment with Guglielmi detachable coils: an in vitro scanning electron microscopic study

BACKGROUND AND PURPOSE

In the 1990s, the introduction of the Guglielmi detachable coil (GDC) system in clinical practice was followed by extensive clinical use of this endovascular device in the treatment of brain aneurysms. This technology is based on electrothrombosis and electrolytic detachment of platinum coils. Despite the extensive use of this treatment technique, the role of electrothrombosis has not been fully investigated and clarified. An in vitro electron microscopic study of human blood was performed to elucidate the role that electrothrombosis might play in triggering the biologic response of thrombosis of the aneurysmal sac.

METHODS

Human blood from five patients was used to fill plastic containers in which GDCs had been deposited. These five patients had subarachnoid hemorrhage and were similar in age and clinical presentation. Electron microscopic studies were performed on GDCs that had been electrically charged and on GDCs that had not.

RESULTS

All electron microscopic studies revealed that the electrically charged GDCs were covered by blood elements and fibrin adherent to the surface of the coil. Noncharged GDCs did not have deposits or adhesions of these blood constituents.

CONCLUSION

These findings demonstrated that passage of electric current through the GDC induces attraction of blood constituents. This attraction may trigger a thrombotic reaction on the surface of the coil. The greater the time of current application, the more pronounced the cellular reaction and the deposition of fibrin and blood cells on the GDC.

Characteristics of cerebral microembolism during carotid stenting and angioplasty alone

BACKGROUND

Cerebral microembolism has often been documented by transcranial Doppler imaging during carotid angioplasty and stenting. However, few data are available about its characteristics during the 2 different kinds of procedure.

OBJECTIVES

To compare the incidence of microemboli occurring during angioplasty alone with that during stenting in the different phases of the procedures and to relate it to periprocedural cerebrovascular complications.

PATIENTS AND METHODS

Thirty-eight patients underwent 41 procedures (15 angioplasty alone and 26 stenting) for symptomatic carotid stenoses of 70% or more. Transcranial Doppler monitoring was performed to detect microemboli in the middle cerebral artery during 3 phases of the procedure: (1) guidewire crossing, (2) first dilatation in case of angioplasty alone or stent release with predilatation if performed, and (3) further dilatation.

RESULTS

Microemboli occurred in all cases in phase 1 of the procedure but less frequently in the arteries treated with stenting when compared with those treated with angioplasty alone in phase 2 and particularly (P<.02) in phase 3. The mean number of microemboli was highest in phase 2, predominant (P<.05) during angioplasty alone, and particularly reduced (P<.02) in phase 3 during the stenting procedures. During 2 (5%) of the 41 procedures, cerebrovascular complications occurred in phase 1, with the number of microemboli being higher than mean values.

CONCLUSIONS

Cerebral microembolism is a very common event, especially during guidewire crossing and angioplasty alone compared with stenting. Further studies concerning the prognostic significance of this are advisable.

Acute histologic and ultrastructural study in one case of human basilar tip aneurysm embolised with guglielmi detachable coils

SUMMARY

Histologic findings after Guglielmi detachable coils endovascular embolisation have been studied in experimental aneurysms. Few reports describe histopathologic reactions to platinum coils in humans. In this report we describe gross, light microscopic pathology and scanning electron microscopy study of a ruptured basilar tip artery aneurysm in a patient who died 16 hours following coiling.

Superselective intraarterial fibrinolysis in central retinal artery occlusion

Intraarterial fibrinolysis was performed in three patients with acute central retinal artery occlusion using recombinant tissue plasminogen activator as a fibrinolytic agent. In two cases the ophthalmic artery was selectively catheterized, and in the other a thrombolytic drug was infused into the ophthalmic artery by way of the meningeal collaterals. All patients experienced visual improvement. Fibrinolysis can produce better results than obtained from conservative treatment. A good prognosis can be achieved if the treatment starts within the first 4 to 5 hours after occlusion.

Epidural spinal cavernous hemangioma

STUDY DESIGN

Five cases of epidural spinal cavernous hemangioma submitted to magnetic resonance imaging and surgery were reviewed.

OBJECTIVE

To correlate different magnetic resonance imaging appearances of epidural spinal cavernous hemangioma with histologic findings.

SUMMARY OF BACKGROUND DATA

Cavernous hemangioma is an uncommon vascular malformation that may occur anywhere in the central nervous system. Purely epidural lesions are very rare. Accurate correlation between magnetic resonance imaging appearances and histologic findings have not been reported in the literature.

METHODS

Five cases of epidural spinal cavernous hemangioma that had undergone magnetic resonance imaging evaluation followed by microsurgical removal, were retrospectively reviewed. Conventional spin-echo T1-, proton density- and T2-weighted magnetic resonance images were obtained in all cases, and gadolinium was used in all but one. Two cases have also been evaluated with computed tomography.

RESULTS

In two cases, magnetic resonance imaging showed mixed low- and high-signal intensity components in all sequences and pathologic examination showed degenerative phenomena and hemosiderin pigments. In the remaining three cases, magnetic resonance imaging showed low- or intermediate-signal intensity on T1-weighted and high-signal intensity on proton density- and T2-weighted images. In those cases, pathologic examination showed an absence of degenerative phenomena and no signs of hemorrhage. All patients underwent surgery by laminectomy and microsurgical resection. In all, significant improvement was obtained.

CONCLUSIONS

Epidural spinal cavernous hemangioma has a different magnetic resonance imaging appearance probably because of the presence or absence of the degenerative phenomena and hemosiderin pigments. As in cerebral locations, mixed signal intensity in all sequences on magnetic resonance images might be indicative of cavernous hemangioma. Presumptive preoperative diagnosis of the lesion may render the surgical approach less invasive.

Acoustic neuroma: correlations between morphology and otoneurological manifestations

Forty-two patients with acoustic neuroma (AN) were studied to determine whether different types of neuroma could be correlated with specific signs and symptoms of the disease. Based on gadolinium-enhanced TI-weighted MRI sequences, the 42 cases of AN could be divided into three groups, either by size (small: 11.9%, medium: 50%, and large: 38.1%) or by site of origin of the tumour (lateral: 16.7%, intermediate: 69%, and medial: 14.3%). Relations were found between the size and the site of origin of the neuromas and certain clinical, audiological and vestibular findings. The clinical presentation seemed to vary with the site of origin and the size of the tumour: patients with lateral neuromas generally had small tumours, sometimes only located in the internal auditory canal (IAC), and presented early subjective hearing loss while patients with medial neuromas had larger tumours which grew without causing significant audiological symptoms. Normal hearing function was seen only in the patients with medial ANs; however, a significant relation between the size or the site of origin of the AN and the average hearing threshold was not demonstrated. The sensitivity of the stapedial reflex test (SR) was higher for lateral ANs. Anomalies in the brainstem auditory evoked potentials (BAEPs) did not seem to be related to either the size or the site of origin of the AN. The vestibular tests demonstrated a higher frequency of central vestibular involvement in the large tumours, while normal function was more frequent in the lateral tumours. In the group studied the combination of BAEPs and vestibular tests allowed us to identify all the ANs with an optimal level of sensitivity.

Anterior fossa dural arteriovenous malformation discovered by means of PW-Doppler examination

One case of dural arteriovenous malformation in the base of the anterior cranial fossa is reported. It was discovered by means of a PW-Doppler examination of angular branch of the ophthalmic artery in a patient under observation for hypertrophy of a superficial temporal artery. The nidus was located in the region of the cribriform plate and fed by the anterior ethmoidal arteries of both sides, draining into the superior sagittal sinus, via pial enlarged veins. The patient successfully underwent surgical treatment and a post-operative PW-Doppler confirmed normalization of the flow pattern in the angular branches of both ophthalmic arteries.

MR angiography of spinal vascular malformations

PURPOSE

To determine the potential and limitations of MR angiography in the evaluation of spinal vascular malformations.

METHODS

Eleven consecutive patients with spinal vascular malformations proved with spinal selective arteriography underwent two-dimensional phase-contrast MR angiography.

RESULTS

Abnormal vessels within the spinal canal were identified with MR angiography in 10 patients. In 1 patient with a dural arteriovenous fistula no definite vascular abnormality was seen with MR angiography. Correlation of MR angiography with spinal selective arteriography showed that the former allowed identification of the arterial feeder in 3 patients with intramedullary arteriovenous malformations and 2 with perimedullary arteriovenous fistula, whereas the source of intradural draining vein was seen in only 2 of 6 patients with dural arteriovenous fistula.

CONCLUSION

MR angiography is a promising complementary tool to MR imaging for detection and characterization of spinal vascular malformations.