[CT and MRI features of arachnoid cyst of the petrous apex: report of 3 cases]. / Aspects TDM et IRM du kyste arachnoïdien de l'apex pétreux.

PURPOSE: To describe the CT and MRI features of 3 cases of arachnoid cyst of the petrous apex. PATIENTS AND METHODS: Three patients with isolated trigeminal neuralgia, trigeminal hypoesthesia, and sinusitis. Axial and coronal CT images were obtained. T1W, FSE T2W, FLAIR, T2*W and diffusion-weighted MR sequences were obtained. RESULTS: In all cases, both CT and MRI showed expansile lesions eroding the petrous apex. Lesions were hypodense on CT and isointense to CSF on MRI, without contrast enhancement. In one case, the lesion was contiguous with Meckel's cave with temporal fossa and sphenoid sinus extension. CT and MR imaging features are useful to distinguish arachnoid cysts of the petrous apex from other benign lesions of the petrous apex. CONCLUSION: CT and MRI imaging features allow diagnosis of arachnoid cyst of the petrous apex because its imaging features, especially on DWI, are different from other cystic lesions of the petrous apex, namely cholesteatoma. It should be considered in patients with trigeminal involvement, especially trigeminal neuralgia.

Occlusion of the middle cerebral artery due to synthetic fibers.

We report an unusual etiology for a thromboembolic complication. Occlusion of the middle cerebral artery occurred before embolization of an intracranial aneurysm. Attempts to recanalize the artery failed by using both fibrinolytics and IIb/IIIa inhibitors but succeeded with mechanical thrombectomy with a micro-snare. Pathologic analysis of the thrombus showed numerous synthetic fibers that were determined to have originated from unsealed gauze that was used during the procedure.

Carotid stenting for radiation-induced stenoses: A report of 7 cases.

BACKGROUND AND PURPOSE: Radiation-induced stenoses of the carotid artery are associated with fibrosis of the arterial layers and tissue planes that renders their surgical treatment difficult. We present our clinical experience in carotid angioplasty stenting (CAS) of patients harboring such stenoses. METHODS: Seven patients underwent transfemoral CAS of 10 radiation-induced stenoses located on either the common or the internal carotid artery. Six patients presented neurological symptoms. Four patients had undergone previous radical neck dissection, and 3 had permanent tracheostomies. Stenoses were primarily covered with a self-expandable stent before carotid dilation. RESULTS: All interventions were successful, with residual stenoses <20%. No permanent complication occurred. The mean follow-up was 8 months. Patients were symptom free at the last clinical examination, and Doppler control showed no evidence of restenosis. CONCLUSIONS: Carotid stenting appears very attractive for such "hostile neck" patients and seems a safe and efficient treatment for radiation-induced stenoses.

Vascular malformations of the spinal cord: intrathecal perimedullary arteriovenous fistulas fed by medullary arteries.

We studied eleven patients with intrathecal extramedullary arteriovenous fistulas identified by selective angiography and myelography. The fistulas were located on the surface of the cord, fed by medullary arteries. Angiography distinguished three separate types that gave identical clinical disorders. Therapeutic results of surgery and embolization allowed specific indications to be defined for treatment of each type of fistula.

Thrombolysis of extracranial and intracranial arteries after IV abciximab.

Abciximab was administered intravenously to three patients to treat thrombus associated with atherosclerotic stenosis of a supra-aortic artery. In two cases, the thrombi had been identified on a previous angiography more than a week before treatment. Successful thrombolysis was achieved with abciximab in all three cases. In this small series, abciximab had a thrombolytic effect on established thrombi that were refractory to previous antithrombotic treatment attempts.

Linac radiosurgery for cerebral arteriovenous malformations: results in 169 patients.

PURPOSE: To present the SALT group results using Linac radiosurgery (RS) for AVM in 169 evaluable patients treated from January 1990 thru December 1993. METHODS AND MATERIALS: Median age was 33 years (range 6-68 years). Irradiation was the only treatment in 55% patients. Other treatment modalities had been used prior to RS in 45%: one or more embolizations in 36%, surgery in 6%, and embolization and surgery in 3% patients. Nidus were supratentorial in 94% patients, infratentorial in 6% patients. Circular 15 MV x-ray minibeams (6-20 mm) were delivered in coronal arcs by a GE-CGR Saturne 43 Linac. Patient set-up included a Betti arm-chair, a Talairach frame. Prescribed peripheral dose was 25 Gy on the 60%-70% isodose (max dose 100%). Arteriographic results were reassessed in December 1997 at 48 to 96 months follow-up. RESULTS: The overall obliteration rate (OR) was 64% (108/169). AVM volumes ranged from 280 to 19,920 mm(3), median 2460 mm(3). OR was 70% for AVM

Facial port-wine stains and Sturge-Weber syndrome.

A retrospective study was made of 106 cases of facial port-wine stains. It was concluded that only patients with lesions located in the ophthalmic (or V1 trigeminal) cutaneous area are at risk for associated neuro-ocular symptoms. It is proposed that Sturge-Weber syndrome results from a dysmorphogenesis of cephalic neuroectoderm.

Management of alarming hemangiomas in infancy: a review of 25 cases.

During the past 10 years, 25 infants with alarming hemangiomas--lesions that impaired important functions and were life threatening, especially when there was visceral involvement--have been treated. A vascular mark was present at birth in 68% of these infants. Visceral hemangiomas were associated with bulky cervicocephalic hemangiomas or with small hemangiomas scattered over the body. Among the 25 infants, 12 had laryngeal hemangiomas, 3 had hepatic hemangiomas, and 1 had gastrointestinal hemangiomatosis. Ocular sequelae, malocclusion, and cutaneous distortion were the most important functional problems. Corticosteroid treatment was used for 23 of 25 infants with alarming hemangiomas. There was a varied treatment response: total failure (30% of the patients); excellent, dramatic, rapid improvement (30% of the patients); and moderate, doubtful response, with the natural course of the disease remaining unaltered (40% of the infants). Arterial embolization, used in 6 infants, gave inconstant results. Cardiac failure, frequently associated with large cutaneous hemangiomas and always seen with hepatic multinodular hemangiomas, required digitalization. In some cases arterial embolization reduced the increased cardiac output. Liver hemangiomas had a high mortality; all 3 infants with hepatic involvement died.

Biodegradable starch microspheres for cerebral arterial embolization.

RATIONALE AND OBJECTIVES: Various materials have been used to perform intracerebral and cervical arterial embolization for head and neck tumors and vascular malformations. This preliminary prospective study was designed to analyze the clinical and histopathologic consequences of arterial embolization into the brain using biodegradable starch microspheres. METHODS: A new arterial embolization procedure which ensured the integrity of the common and internal carotid arteries, without modifying the arterial flow, was designed. The procedure allowed for cerebral arterial microembolization in 20 Sprague-Dawley rats. Various amounts of biodegradable starch microspheres (Spherex) were introduced into the brain via the left external carotid artery. RESULTS AND CONCLUSIONS: Clinical and histopathologic results suggested that: 1) consequences of cerebral embolization using biodegradable starch microspheres are related to the amount of material embolized; and 2) Spherex microspheres behave differently from degradable microspheres in the brain. Despite the rapid biodegradability of the material, permanent damage from ischemia to the brain was noted.

Arterial blood supply to the uterus in nonpregnant sheep: a pertinent model for clinical practice?

RATIONALE AND OBJECTIVES: Our goal was to study the arterial supply to the sheep uterus to compare its similarity with that of women and to evaluate the interest of this animal model for training in uterine artery embolization. METHODS: Ten nonpregnant sheep underwent aortography and selective study of the ovarian, internal iliac, uterine, and vaginal arteries. RESULTS: The uterus was supplied mainly by the uterine arteries in all sheep. The ovarian artery, which was identified in five sheep, had a thin anastomosis with the ipsilateral uterine artery at the tubal junction. The vaginal artery provided blood flow to the inferior part of the cervix and anastomosed with the ipsilateral uterine artery. CONCLUSIONS: Because uterine vascularization of nonpregnant sheep is similar to that of women, the sheep represents an appropriate model for experimental uterine artery embolization. This model should be used for interventional radiologists in training not familiar with endovascular navigation inside pelvic arteries.

Pregnancy after embolization of uterine myoma: report of 12 cases.

OBJECTIVE: To treat uterine myomas with embolization, to look for pregnancy-induced myoma recurrences, and to assess pregnancy course and outcome after embolization. DESIGN: Observational clinical study. SETTING: University of Paris VII hospital. PATIENT(S): Nine women had embolization for symptomatic myoma, with 12 pregnancies observed. INTERVENTION(S): Embolizations were highly selective and performed bilaterally through the uterine arteries with polyvinyl alcohol. MAIN OUTCOME MEASURE(S): Pregnant women were evaluated by physical and sonographic examinations. RESULT(S): Before embolization, the mean uterine volume was 450 cm(3), and in six patients polymyomas were present. The median age at embolization was 40 years; the median delay before pregnancy was 9 months; and the median age at first pregnancy outcome was 41 years. Five early miscarriages occurred. The seven other pregnancies were uneventful, although three premature births and one case of late toxemia occurred unrelated to previous embolization. Three women delivered vaginally and four by cesarean section. Neither myoma recurrence nor abnormality in uterine function was observed. CONCLUSION(S): The results of this first series of 12 pregnancies after myoma embolization are promising. If these preliminary results are confirmed, embolization could be a major breakthrough in the management of myoma and could replace conventional medical and surgical treatments.

Endovascular treatment of a giant fusiform aneurysm of the entire basilar artery.

The authors describe a case of fusiform basilar artery aneurysm not amenable to surgical clipping or balloon occlusion with preservation of the parent artery. The aneurysm was treated by balloon occlusion (proximal basilar artery) after test occlusion was well-tolerated; 7-year follow-up showed good results.

Spontaneous disappearance of a spinal dural arteriovenous fistula.

A case of proved regression of an asymptomatic dural arteriovenous fistula is reported. At the time of diagnosis, myelography showed dilated perimedullary veins. Angiography demonstrated a radicular outflow from these veins to the epidural plexus. A follow-up angiogram 5 years later was normal.

Embolization of spinal cord vascular malformations via the anterior spinal artery.

During a 3 year period, 21 patients with spinal cord vascular malformations involving the anterior spinal artery were treated by embolization through this artery. Of four cases of extramedullary arteriovenous fistula, two patients embolized at an early stage showed excellent results, whereas results were mediocre in two patients who were paraplegic at embolization. Of 17 cases of intramedullary arteriovenous malformation (AVM), nine patients showed clinical improvement either with or without radiologic evidence of residual malformation; three patients had complications that led to clinical worsening; in the other five patients, results were mixed or inconclusive. Angiomyelotomography is recommended to diagnose extramedullary arteriovenous fistulae involving the anterior spinal artery. Pretherapeutic evaluation of intramedullary AVMs must consider the spinal cord level at which the malformation occurs. Angiotomography and temporary occlusion tests permit identification of collateral anastomoses before embolization. Respective criteria for surgery and embolization are defined. In cases where embolization is indicated, short-term results can generally be predicted.

Giant extramedullary arteriovenous fistula supplied by the anterior spinal artery: treatment by detachable balloons.

A case of a large extramedullary arteriovenous fistula in a young man, which was deemed inoperable, is described. The fistula was mainly supplied by the anterior spinal artery and was responsible for a progressive myeloradicular syndrome. Successful treatment with detachable balloons was carried out. Along with this case report, a review is made of the different types of extramedullary arteriovenous fistulas and their treatment based upon 11 cases seen at Lariboisière Hospital: type 1 is a plain small fistula where embolization is contraindicated; type 2 shows an enlarged anterior spinal artery with dysplastic vein and may be embolized with solid particles; type 3 is a very large multipediculated fistula where the best treatment seems to be detachable balloons. The indications for using detachable balloons for temporary occlusion and for definitive treatment are reviewed. Special emphasis is placed on the possibility of detaching balloons without the need for a coaxial catheter.

Percutaneous transvenous embolization through the thrombosed sinus in transverse sinus dural fistula.

Each of two patients presented with a dural arteriovenous fistula involving the transverse sinus. The sinus was thrombosed proximal and distal to the dural arteriovenous fistula with the venous drainage being retrograde through cortical veins. An ipsilateral percutaneous transjugular approach was used in both cases and allowed recanalization of the thrombosed sinus and embolization of the dural arteriovenous fistula with coils. Complete cure was achieved in one patient and 95% reduction in arteriovenous shunting including elimination of the cortical venous reflux in the other. This technique avoided surgical exposure of the sinus.

Embolization of arteriovenous malformations of the temporal lobe via the anterior choroidal artery.

The indications, technique, and results of embolization of arteriovenous malformations with liquid adhesive agents delivered through the anterior choroidal artery are reported. Arteriovenous malformations of the temporal lobe were found in four patients with intracerebral bleeding and two with intractable epilepsy. In five of the six, the dominant arterial feeder was the anterior choroidal artery. All patients underwent superselective catheterization of the anterior choroidal artery and embolization of the arteriovenous malformation. Complications related to the anterior choroidal artery embolization developed after embolization in one patient, after which we changed our technique of embolizing arteriovenous malformations via this artery. A thorough understanding of the functional anatomic structures supplied by each segment of the artery is important. Guidelines for safe catheterization and embolization are given. Embolization of arteriovenous malformations fed predominantly by the anterior choroidal artery is difficult and dangerous. An understanding of the functional anatomy of this artery and proper technique can enable successful embolization of arteriovenous malformations via this route.

Aneurysms of spinal arteries associated with intramedullary arteriovenous malformations. I. Angiographic and clinical aspects.

PURPOSE: To evaluate the nature of aneurysms of the spinal arteries, their relative frequency, and the risks associated with these lesions. METHODS: We retrospectively reviewed the spinal angiographic studies of 186 patients with spinal cord vascular malformations--70 intramedullary AVMs, 44 extra (peri) medullary AV fistulas, and 72 dural AV fistulas. RESULTS: Fifteen spinal artery aneurysms (SAs) in 14 out of 70 patients (20%) with an intramedullary AVM were discovered. No SAs were observed in the other types of spinal vascular malformations. The intramedullary AVMs with SAs were cervical in seven cases and thoracic in the other seven cases (one of the thoracic had two SAs). Fourteen SAs were located on a major feeding vessel to the associated intramedullary AVM (10 on the anterior spinal artery and four on a posterior spinal artery and only one SA was located remote from the AVM feeding vessels. This remote aneurysm was located on the intercostal artery feeding a vertebral angioma in a patient with metameric angiomatosis. Subarachnoid hemorrhage occurred in all cases of SA. The presence of a SA carried a statistically significant (P less than .05) increase in the risk of bleeding. CONCLUSIONS: Although increased blood flow seems to be an important factor in formation of these SAs associated with intramedullary AVMs, the role of a developmental vascular anomaly must be stressed: metameric angiomatosis was found in six out of the 14 patients (43%).

Aneurysms of spinal arteries associated with intramedullary arteriovenous malformations. II. Results of AVM endovascular treatment and hemodynamic considerations.

PURPOSE: To evaluate the changes occurring in spinal aneurysm (SA) size related to modification of endovascularly treated AVMs. METHODS: Fourteen patients with an intramedullary AVM and associated SA underwent endovascular treatment of their AVM with particles. Embolization sessions numbered from one to 14 (mean five) in each patient. RESULTS: Four patients had SAs with size changes mirroring those of the AVM with embolization: these decreased in size or disappeared after AVM reduction or cure and increased or recurred after AVM recanalization. A second group of patients had SAs that remained unchanged despite AVM changes (six of seven of these were in patients with metameric angiomatosis). CONCLUSIONS: Results in the first group lend support to the hemodynamic theory of associated aneurysm formation. On the other hand, aneurysms that remained unchanged probably are not AVM flow-related and could be an expression of an extensive vascular disorder such as metameric angiomatosis; however, hemodynamic and developmental factors could be concurrent.

Trisacryl gelatin microspheres for therapeutic embolization, I: development and in vitro evaluation.

PURPOSE: To develop a precisely calibrated, perfectly spherical, stainable, soft, and implantable but nonresorbable particulate embolization material. METHODS: Calibrated particles with a trisacryl gelatin polymer core and hydrophilic surface characteristics were obtained by reversed emulsion synthesis followed by application of a wet-sieving technique. Particles were suspended in saline, bottled, and sterilized. Quality control included analysis of particle diameters before and after sieving and of suspension sterility and apyrogenicity. Particles were subsequently tested to ascertain their compatibility with commercially available microcatheters. RESULTS: The resulting embolization material consisted of spherical, stainable microspheres of medical grade with diameters ranging from 130 microns to 1200 microns. Sieving the suspension produced particle groups of homogeneous size (accuracy, +/- 20-100 microns). At injection, the particles showed no tendency to build aggregates or to obstruct the microcatheters. CONCLUSION: Precisely calibrated and easy-to-use microspheres were obtained that satisfied the biomedical requirements for implantation as an embolization material.