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Biomedical subjects

R Willinsky

Publications and source records attributed to R Willinsky.

At least 19 recordsLinked to original sources
PubMed2002

Spontaneous regression of cerebral arteriovenous malformations: clinical and angiographic analysis with review of the literature.

Spontaneous regression of cerebral arteriovenous malformation (AVM) is rare and poorly understood. We reviewed the clinical and angiographic findings in patients who had spontaneous regression of cerebral AVMs to determine whether common features were present. The clinical and angiographic findings of four cases from our series and 29 cases from the literature were retrospectively reviewed. The clinical and angiographic features analyzed were: age at diagnosis, initial presentation, venous drainage pattern, number of draining veins, location of the AVM, number of arterial feeders, clinical events during the interval period to thrombosis, and interval period to spontaneous thrombosis. Common clinical and angiographic features of spontaneous regression of cerebral AVMs are: intracranial hemorrhage as an initial presentation, small AVMs, and a single draining vein. Spontaneous regression of cerebral AVMs can not be predicted by clinical or angiographic features, therefore it should not be considered as an option in cerebral AVM management, despite its proven occurrence.

Adult↗
PubMed2001

Dural arteriovenous fistula associated with neoplastic dural sinus thrombosis: two cases.

Intracranial dural arteriovenous fistulae are direct arteriovenous shunts within the dura matter. We report two cases of arteriovenous fistulae upstream to a neoplastic dural sinus thrombosis. These cases add further support to the acquired etiology of dural arteriovenous fistulae and to the fact that venous hypertension is one of the most important precipitating factors.

Arteriovenous Fistula↗
PubMed2001

Association of distinct intracranial pial and dural arteriovenous shunts.

Intracranial pial and dural arteriovenous shunts may exist at different sites in the same patient. The etiology, natural history and treatment of these associated conditions have not been completely determined. We reviewed the records of 765 cases of pial arteriovenous malformation and 137 dural arteriovenous fistulae and malformations. We selected eight patients with both pial and dural arteriovenous shunts, separate anatomically, with distinct feeding arteries and draining veins, representing 1% of pial and 17% of dural shunts. Presentation was related to the dural lesion in 5 cases (62.5 %) and to the pial malformation in three (37.5%). Treatment of these lesions should be considered separately based on their angio-architecture and natural history.

Adolescent↗
PubMed2000

Use of a second microcatheter in the management of a perforation during endovascular treatment of a cerebral aneurysm.

We describe the management of a perforation during endovascular treatment of a ruptured paraophthalmic aneurysm in a 53-year-old woman. The microcatheter and guidewire perforated the aneurysm during the initial catheterization. Using a second microcatheter, the aneurysm was packed with Guglielmi detachable coils while the first microcatheter was left in place. There were no adverse effects from the procedure, and the patient was discharged in good clinical condition.

Aneurysm↗
PubMed1999

Spontaneous resolution of bilateral traumatic carotid cavernous fistulas and development of trans-sellar intercarotid vascular communication: case report.

BACKGROUND: Bilateral carotid cavernous fistulas may complicate head injury. Spontaneous resolution of post-traumatic direct carotid cavernous fistula is rare. CASE DESCRIPTION We present a case of a 42-year-old female who developed post-traumatic high flow bilateral carotid cavernous fistulas with cortical and deep venous drainage, who had a spontaneous resolution with thrombosis of the cavernous sinus outlets bilaterally and development of a trans-sellar intercarotid vascular communication. To our knowledge this is the first reported case in the literature describing such a phenomenon. CONCLUSION Bilateral direct carotid cavernous fistulas may undergo spontaneous resolution and form a benign trans-sellar intercarotid vascular communication.

Adult↗
PubMed1999

Endovascular occlusion of basilar bifurcation aneurysms with electrolytically detachable coils.

OBJECT: To describe the clinical and angiographic results of endovascular occlusion of basilar bifurcation aneurysms with electrolytically detachable coils, and to identify factors which should be considered in deciding upon surgical or endovascular treatment. METHODS: We report our experience with 40 patients in whom occlusion of basilar bifurcation aneurysms with electrolytically detachable coils was attempted. All patients underwent superselective angiography and attempted embolization with Guglielmi detachable coils (GDCs). Angiographic and clinical results were prospectively recorded. Twenty-eight aneurysms presented with subarachnoid hemorrhage (SAH), 2 were symptomatic and 10 were incidental. RESULTS: Coils were not placed in 10 patients (25%) because of unfavorable anatomy. Complete aneurysm occlusion was achieved at the time of the initial procedure in 13 (32.5%), small neck remnants were present in 13 (32.5%), and in 4 (10.0%) there was obvious residual contrast filling of the aneurysm body. Of 23 patients successfully coiled after SAH, 20 were Grade 1 to 3 and 3 were grade 4 or 5 at the time of treatment. Eighteen (78%) made a good recovery. Procedural mortality was 2.5% and permanent morbidity was 7.5%. There were no permanent complications in patients with unruptured aneurysms. Complete aneurysm occlusion was possible in 10 (56%) of 18 aneurysms with small necks and 3 (14%) of 22 with large necks. Follow-up angiography in 25 of 28 surviving patients (mean, 12 months) demonstrated stability of all completely occluded aneurysms. Incompletely coiled aneurysms had variable results on follow-up angiograms: 15.4% improved, 69.2% worsened, and 15.4% were stable. No aneurysm bled after treatment during clinical follow-up averaging 22 months. CONCLUSIONS: Endovascular treatment of basilar bifurcation aneurysms appears to prevent early aneurysm rebleeding with acceptable rates of morbidity and mortality, but long-term follow-up is required.

Adult↗
PubMed1999

Subarachnoid hemorrhage from vertebrobasilar dissecting aneurysm treated with staged bilateral vertebral artery occlusion: the importance of early follow-up angiography: technical case report.

OBJECTIVE AND IMPORTANCE: Vertebrobasilar dissecting aneurysms are an uncommon but increasingly recognized cause of subarachnoid hemorrhage (SAH). We describe a patient with SAH caused by a dissecting aneurysm involving both vertebral arteries as well as the basilar trunk. The patient was treated successfully with proximal occlusion of the vertebral arteries using endovascular balloon occlusion in two stages. The importance of early follow-up angiography to document progression or resolution of untreated dissections is emphasized. This approach is suggested as definitive treatment for vertebrobasilar dissection in appropriate circumstances. CLINICAL PRESENTATION: A 41-year-old man presented with SAH from spontaneous vertebrobasilar dissection. Angiography revealed aneurysmal dilation of the right vertebral artery and basilar trunk and occlusion of the left vertebral artery. INTERVENTION: The dissecting aneurysm was treated with balloon occlusion of the right vertebral artery. Repeat angiography 2 weeks later demonstrated resolution of the left vertebral occlusion, with restoration of antegrade flow in the basilar trunk and increased filling of the right vertebral and basilar dissecting aneurysms. Balloon occlusion of the left vertebral artery led to aneurysm thrombosis and excellent clinical outcome. CONCLUSION: Bilateral vertebrobasilar dissecting aneurysms are an uncommon cause of SAH. If unilateral proximal vertebral artery occlusion is chosen as the initial treatment, it is essential to document the status of the contralateral vessel using follow-up angiography. Staged bilateral vertebral artery occlusion should be considered in the event of recurrent or progressive aneurysm enlargement. Endovascular balloon occlusion has advantages over proximal clipping of the parent vessel: cranial nerve manipulation is avoided, test occlusion in the awake patient can be performed at the site of permanent occlusion, and therapeutic levels of anticoagulation can be maintained throughout and after the procedure, thus diminishing the likelihood of thromboembolic complications.

Adult↗
PubMed1999

Paravertebral arteriovenous malformations with epidural drainage: clinical spectrum, imaging features, and results of treatment.

BACKGROUND AND PURPOSE: Arteriovenous malformations (AVMs) of the spine or spinal cord can be characterized as spinal cord AVMs, spinal cord and dural arteriovenous fistulas, and AVMs occurring outside the dura but draining into the epidural veins. The purpose of this study was to review the clinical spectrum, imaging features, and results of treatment of paravertebral arteriovenous malformations (PVAVMs) with epidural drainage. METHODS: The clinical records and images of 10 patients with PVAVMs were analyzed retrospectively for clinical presentation, MR findings, angioarchitecture, pathophysiology, treatment efficacy, and clinical follow-up. RESULTS: Seven patients had myelopathy. The MR findings for three of these patients showed spinal cord hyperintensity on T2-weighted sequences and prominent perimedullary vessels. Angiography, performed in two of the three patients, showed evidence of reflux into the perimedullary veins from the PVAVMs. Each of these two patients underwent surgical clipping of the radicular vein leading to the perimedullary veins. In three of the seven patients, there were large epidural veins compressing the cord. Angiography performed in these patients showed large PVAVMs with multiple feeders, which were treated by a combination of transarterial and transvenous embolization. One of the seven patients had an associated spinal cord arteriovenous malformation. In three patients with incidental PVAVMs, cure was achieved by using a combination of coils and liquid adhesives by the endovascular route. CONCLUSION: The clinical presentation of PVAVMs is variable, and symptomatic lesions are the result of compression by epidural veins or of congestive myelopathy. A clear understanding of the anatomy and pathophysiology is necessary to plan treatment. Endovascular techniques are capable of curing the malformation, alleviating the symptoms, or both in a significant proportion of these lesions.

Adolescent↗
PubMed1998

Arterial aneurysms associated with cerebral arteriovenous malformations: classification, incidence, and risk of hemorrhage.

OBJECT: The goal of this study was to develop a classification system for aneurysms associated with arteriovenous malformations (AVMs) based on their anatomical and pathophysiological relationships and to determine the incidence and bleeding rates for these aneurysms as well as the effects of AVM treatment on their natural history. METHODS: Of 632 patients with AVMs, intranidal aneurysms were found in 35 (5.5%) and flow-related aneurysms in 71 (11.2%). Patients with intranidal aneurysms presented more frequently with hemorrhage (72% compared with 40%, p < 0.001) and had a 9.8% per year risk rate of bleeding during follow-up review. Twelve (17%) of the patients with flow-related aneurysms associated with an AVM presented with hemorrhage from an aneurysm, whereas 15 (21%) bled from their AVM. Seventeen patients underwent angiography after AVM treatment (mean 2.25 years). Of 23 proximal aneurysms, 18 (78.3%) were unchanged, four (17.4%) were smaller, and one (4.3%) had disappeared, whereas four (80%) of five distal aneurysms regressed completely and one was unchanged. Sixteen patients underwent angiography after partial AVM treatment (mean 3.8 years). In cases with less than a 50% reduction in the AVM, no aneurysms regressed, although two enlarged and bled. In cases with greater than a 50% reduction in the AVM, two of three distal aneurysms disappeared and five proximal aneurysms were unchanged. CONCLUSIONS: Arterial aneurysms associated with cerebral AVMs may be classified as intranidal, flow-related, or unrelated to the AVM nidus. Intranidal aneurysms have a high correlation with hemorrhagic clinical presentation and a risk of bleeding during the follow-up period that considerably exceeds that which would be expected in their absence. Patients with flow-related aneurysms in association with an AVM may present with hemorrhage from either lesion. Aneurysms that arise on distal feeding arteries near the nidus have a high probability of regressing with substantial or curative AVM therapy.

Adolescent↗
PubMed1997

Spinal epidural arteriovenous fistula with intramedullary reflux. Case report.

A spinal epidural arteriovenous fistula with secondary reflux into the perimedullary veins is a rare entity. The authors present such a case with a discussion of its pathophysiology and treatment. The mechanism for formation of a spinal dural arteriovenous fistula is outlined based on the anatomical substrates in this region.

Aged↗
PubMed1996

The validity of classification for the clinical presentation of intracranial dural arteriovenous fistulas.

A number of classification schemes for intracranial dural arteriovenous fistulas (AVFs) have been published that claim to predict which lesions will present in a benign or aggressive fashion based on radiological anatomy. We have tested the validity of two proposed classification schemes for the first time in a large single-institution study. A series of 102 intracranial dural AVFs in 98 patients assessed at a single institution was analyzed. All patients were classified according to two grading scales: the more descriptive schema of Cognard, et al. (Cognard) and that recently proposed by Borden, et al. (Borden). According to the Borden classification, 55 patients were Type I, 18 Type II, and 29 Type III. Using the Cognard classification, 40 patients were Type I, 15 Type IIA, eight Type IIB, 10 Type IIA+B, 13 Type III, 12 Type IV, and four Type V. Intracranial hemorrhage (ICH) or nonhemorrhagic neurological deficit was considered an aggressive presenting clinical feature. A total of 16 (16%) of 102 intracranial dural AVFs presented with hemorrhage. Eleven of these hemorrhages (69%) occurred in either anterior cranial fossa or tentorial lesions. When analyzed according to the Borden classification, none (0%) of 55 Type I intracranial dural AVFs, two (11%) of 18 Type II, and 14 (48%) of 29 Type III intracranial dural AVFs presented with hemorrhage (p < 0.0001). After exclusion of visual or cranial nerve deficits that were clearly related to cavernous sinus intracranial dural AVFs, nonhemorrhagic neurological deficits were a feature of presentation in one (2%) of 55 Type I, five (28%) of 18 Type II, and nine (31%) of 29 Type III patients (p < 0.0001). When combined, an aggressive clinical presentation (ICH or nonhemorrhagic neurological deficit) was seen most commonly in intracranial dural AVFs located in the tentorium (11 (79%) of 14) and the anterior cranial fossa (three (75%) of four), but this simply reflected the number of higher grade lesions in these locations. Aggressive clinical presentation strongly correlated with Borden types: one (2%) of 55 Type I, seven (39%) of 18 Type II, and 23 (79%) of 29 Type III patients (p < 0.0001). A similar correlation with aggressive presentation was seen with the Cognard classification: none (0%) of 40 Type I, one (7%) of 15 Type IIA, three (38%) of eight Type IIB, four (40%) of 10 Type IIA+B, nine (69%) of 13 Type III, 10 (83%) of 12 Type IV, and four (100%) of four Type V (p < 0.0001). No location is immune from harboring lesions capable of an aggressive presentation. Location itself only raises the index of suspicion for dangerous venous anatomy in some intracranial dural AVFs. The configuration of venous anatomy as reflected by both the Cognard and Borden classifications strongly predicts intracranial dural AVFs that will present with ICH or nonhemorrhagic neurological deficit.

Adolescent↗
PubMed1994

Angiographic embolization for the treatment of epistaxis: a review of 108 cases.

Ninety-seven patients were referred to the Toronto Hospital (Western Division) between January 1984 and January 1992 for selective angiographic embolization (108 embolizations, including repeat procedures) to control intractable or recurrent severe epistaxis. Eighty-one patients (comprising 94 embolizations) were referred on an emergent basis because of failure of conventional conservative therapy, consisting of anterior and posterior packing. The remaining 16 patients (14 embolizations) were referred electively for recurrent epistaxis. A retrospective review of these cases was performed, with long-term telephone follow-up achieved in over 95% of cases. Embolization safely controlled active hemorrhage in 88% of the emergent cases. The success rate increased to 90% when two cases in which the source of epistaxis was found to be from the internal carotid artery were excluded (because these vessels could not be safely embolized). Of the patients whose epistaxis was initially controlled by embolization, 82% had no further nosebleeds (follow-up time ranged from 2 to 82 months; average, 26.8 months). More than half of the long-term failures were seen in patients with Osler-Weber-Rendu disease. Overall, the mortality rate was 0% and the long-term morbidity rate was 2% (one cerebral vascular accident and one case of skin slough in the territory of the superficial temporal artery.

Adolescent↗
PubMed1994

Venous congestion: an MR finding in dural arteriovenous malformations with cortical venous drainage.

PURPOSE: To present the MR findings of intracranial dural arteriovenous malformations with cortical venous drainage, emphasizing the parenchymal changes. METHODS: Conventional MR and x-ray angiograms in 13 patients with dural arteriovenous malformations and cortical venous reflux were reviewed. The site of the shunt, location of the venous reflux, and presence of venous stenosis were assessed on the angiograms. Parenchymal changes, dilated vessels, and venous occlusive disease were assessed on MR. RESULTS: On MR, 10 of the 13 patients (77%) had dilated pial vessels. Two patients had hydrocephalus. Two patients presented with parenchymal bleeds, one with a subdural component, both remote from the nidus. Two patients presented with subarachnoid hemorrhage. One patient had a parenchymal bleed 9 months after presentation. Venous occlusion was evident on MR in 2 patients. Diffuse white matter edema in the cerebellar or cerebral hemispheres was present on MR in 4 patients and correlated with neurologic deficits. In 2 of these 4 patients, gadolinium enhancement was seen in the periphery of the involved hemisphere. CONCLUSIONS: On MR a surplus of pial vessels suggests a dural arteriovenous malformation with cortical venous drainage. The MR finding of white matter edema deep in the cerebral or cerebellar hemispheres is direct evidence of a venous congestion.

Adult↗
PubMed1993

Posterior fossa surgery: an unusual cause of superficial siderosis.

With the widespread use of magnetic resonance imaging, an increasing number of cases of superficial siderosis are being discovered. However, the cause remains uncertain in almost half the cases. We report a case where previous surgery for a pontine hematoma established a pathway for extravasation of blood into the 4th ventricle, resulting in superficial siderosis that was demonstrated on a follow-up magnetic resonance imaging scan 8 years later. This case presents an unusual iatrogenic cause of superficial siderosis that has not been reported previously.

Brain Neoplasms↗
PubMed1992

Combined PTCA and microcoil embolization of a left internal mammary artery graft.

Internal mammary arteries are increasingly common conduits for coronary revascularization. Although infrequent, cardiologists are faced with a number of technical failures. We describe a case of combined PTCA to a LIMA insertion stenosis, along with coil embolization of a large unligated intercostal side branch. A complication of embolization is described along with angiographic follow-up.

Angina Pectoris↗
PubMed1992

Superselective angiography of a spinal dural arteriovenous fistula having a common segmental origin with the artery of Adamkiewicz.

The artery of Adamkiewicz infrequently originates from the same radicular vessel that also supplies a dural arteriovenous fistula. This variant is not adequately emphasized in the neuroradiological literature. Awareness of this entity is essential to prevent catastrophic complications during embolization. We report such a case, and our experience with attempted embolization. We are unaware of any previously reported instance of such an attempt being made.

Adult↗
PubMed1992

Rapid postanoxic calcification of the basal ganglia.

A 22-year-old male diabetic on hemodialysis suffered a cerebral anoxic event. Serial CT showed the development of basal ganglia calcification over a period of no more than 17 days. It appears that the basal ganglia may develop petechial hemorrhage, necrosis, calcification, or combinations of these following an anoxic insult. The neuropathologic substrate and mechanism of rapid postanoxic calcification are unknown.

Adult↗