Jean-Jacques Merland

Arterial embolisation to treat uterine myomata

Haemorrhage, probably related to hypervascularisation, is the commonest complication of uterine myomata and is difficult to treat. 16 patients, aged 34-48 years, with symptomatic uterine myomata, for which a major surgical procedure was planned after failure of medical treatment, were treated by selective free-flow arterial embolisation of the myomata with Ivalon particles. With a mean follow-up of 20 months (range 11-48) in the responders, symptoms resolved in 11 patients; menstrual cycles returned to normal in ten of these. Three patients had partial improvement. Two failures required surgery. In 14 cases embolisation caused pelvic pain, which required analgesia in all.

Intradural Perimedullary Arteriovenous Fistulae: Results of Surgical and Endovascular Treatment in a Series of 35 Cases

A series of 35 patients treated for an intradural perimedullary arteriovenous fistula (AVF) between 1970 and 1990 is reported. Angiography was performed on all of the patients, leading to the diagnosis. The patients were classified into Type I (4 patients), Type II (9 patients), and Type III (22 patients). One Type I patient was not treated, two others underwent surgery, and the last one was embolized. All of the Type II AVFs were treated, two by embolization, four by direct surgery, and three by surgery after incomplete embolization. All of the Type III AVFs were treated by endovascular detachable silicone balloon. Complete occlusion of the AVF was achieved in all treated cases of Types I and II AVF and in 15 cases of Type III AVF; for the 6 other cases of Type III AVF, incomplete occlusion was achieved. In the Types I and II AVFs, partial improvement was clinically observed in only half of the patients; the others remained unchanged. The 15 patients whose Type III AVF was completely embolized recovered completely, and four patients with Type III AVF who were incompletely embolized remained unchanged; 2 other patients with Type III AVF worsened after incomplete occlusion, and 1 additional patient died a few hours after an attempt of endovascular occlusion of a cervical Type III AVF. The place of the perimedullary AVFs among the other vascular malformations involving the spinal cord is discussed according to this classification into three types. Their specific diagnostic and therapeutic difficulties are discussed, resulting in a simplified classification including two types of perimedullary AVF.

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 </= 4200 mm(3) 4200 mm(3) (p 25 mm (p = 0.04). OR was 71%, in the absence of embolization, vs. 54% for previously embolized nidus (p = 0.03). OR was 71% for monocentric RS vs. 54% for multi-isocenters (p 28 Gy vs. 55% for values </= 28 Gy (p 79% vs. 57% for lower values (p 17 Gy, vs. 59% for mLd </= 16 Gy (p 40%, vs. 54% for mLi </= 40% (p 85% vs. 60% for CR </= 84% (NS). For patients treated according to our protocol, i.e., 24-26 Gy on the 60%-70% isodoses, OR was higher (68%) than for other patients (47%) (p = 0.02). After multivariate analysis, absence of previous embolization and mono isocentric-irradiation were independent factors predicting obliteration. Complications were: recurrent hemorrhage, 4 patients (1 patient died); brain necrosis on MRI, 2 patients; subsequent epilepsy, 4 patients; other subsequent neurologic deficits, 3 patients. CONCLUSION Overall OR was 64% (48-96 months follow-up). After monovariate analysis higher ORs were associated with smaller volumes </= 4200 mm(3), smaller nidus size </= 25 mm, absence of prior embolization, monoisocentric RS, higher values for mean and minimum lesion doses and compliance to our protocol. Higher values for the peripheral dose and isodose tended to give better results. Multivariate analysis showed that the absence of prior embolization and monoisocentric irradiation were independent factors predicting successful irradiation.

Dural arteriovenous fistulas as a cause of intracranial hypertension due to impairment of cranial venous outflow

OBJECTIVES A retrospective study was carried out on 13 patients with intracranial dural arteriovenous fistulas (DAVFs) who presented with isolated or associated signs of intracranial hypertension. METHODS Nine patients presented with symptoms of intracranial hypertension at the time of diagnosis. Ocular fundoscopy available in 12 patients showed bilateral papilloedema in eight and optic disk atrophy in four. Clinical evolution was particularly noticeable in five patients because of chronic (two patients) or acute (after lumbar shunting or puncture: three patients, one death) tonsillar herniation. RESULTS Two patients had a type I fistula (drainage into a sinus, with a normal antegrade flow direction). The remaining 11 had type II fistulas (drainage into a sinus, with abnormal retrograde venous drainage into sinuses or cortical veins). Stenosis or thrombosis of the sinus(es) distal to the fistula was present in five patients. The cerebral venous drainage was abnormal in all patients. CONCLUSION Type II (and some type I) DAVFs may present as isolated intracranial hypertension mimicking benign intracranial hypertension. Normal cerebral angiography should be added as a fifth criterion of benign intracranial hypertension. The cerebral venous drainage pattern must be carefully studied by contralateral carotid and vertebral artery injections to correctly evaluate the impairment of the cerebral venous outflow. Lumbar CSF diversion (puncture or shunting) may induce acute tonsillar herniation and should be avoided absolutely. DAVF may induce intracranial hypertension, which has a poor long term prognosis and may lead to an important loss of visual acuity and chronic tonsillar herniation. Consequently, patients with intracranial hypertension must be treated, even agressively, to obliterate the fistula or at least to reduce the arterial flow and to restore a normal cerebral venous drainage. The endovascular treatment may associate arterial or transvenous embolisation and /or surgery. Patients in whom the fistula is not obliterated after an endovascular therapeutic procedure, need continous clinical and angiographical follow up.

Angioarchitecture associated with haemorrhage in cerebral arteriovenous malformations: a prognostic statistical model

Abstract The overall haemorrhagic risk of a cerebral arteriovenous malformation (cAVM) is 2–4 % per year. However, the individual risk of haemorrhage has never been determined. This study was undertaken to assess the haemorrhage risk of an individual cAVM. Neuroangiographic findings of 160 cAVM were analysed retrospectively, looking at 30 angiographic features. A statistical model was established by logistic regression to evaluate the risk of an individual cAVM. We statistically correlated 15 parameters with the haemorrhage risk. The statistical model includes five independent parameters. Four are unfavourable: exclusively deep drainage, venous stenoses, venous reflux and the radio of afferent to efferent systems; one is favourable: venous recruitment. This model quantifies the individual risk of haemorrhage. When this model is applied to the population studied, the error rate is 5 %. This model can contribute to therapeutic strategy, and to a better understanding of the natural history of cAVM.

Long-term changes in intracranial dural arteriovenous fistulae leading to worsening in the type of venous drainage.

Abstract We review seven patients with intracranial dural arteriovenous fistulae (ICDAVF), each altering the initial type of venous drainage to one with a higher grading during long-term follow-up. Five were discovered due to symptoms of intracranial hypertension, two due to changes in tinnitus and one case following subarachnoid haemorrhage. In five cases, cortical venous drainage developed during the follow-up period. Three different mechanisms were observed: stenosis or thrombosis in the draining veins in 4 cases: increased arterial flow in 2; and the appearance o a new fistula site or extension of the initial shunt in 2. Type I and type II a fistulae which are not completely cured, require both close clinical observation and Doppler examinations in the follow-up period. Any charge in the clinical pictures indicates a repeat angiogram. Stenosis of the venous drainage, forecasting later worsening in the venous outlet, requires more thorough angiographic follow-up.

Percutaneous Transvenous Catheterization and Embolization of Vein of Galen Aneurysms

Seven cases of vein of Galen aneurysms treated by percutaneous transvenous endovascular occlusion of the aneurysmal vein are presented. In one case, the approach was via the femoral vein, and in the other six cases, by the jugular vein. All of the malformations were multipedicular and, additionally, in six of the seven there was an intervening arterial-arterial network between the posterior thalamoperforating arteries and the wall of the venous aneurysm. This fistulous network was interpreted as purely arterial and not as an associated arteriovenous malformation. For this reason, the transvenous approach was considered justified, and was performed without risk of hemorrhage caused by retrograde venous hypertension. Measurement of intra-aneurysmal pressure during the course of treatment allowed better understanding of the hemodynamics of the lesions, guided the amount of occlusion to be accomplished during each treatment session, and thus may have prevented the phenomenon of normal perfusion pressure breakthrough. The percutaneous transvenous approach offers all the advantages of the transtorcular approach but avoids surgery. Because of our excellent angiographic and clinical results--five complete and two partial occlusions, with favorable outcomes and no major complications--we believe that this technique is better for the treatment of multipedicular vein of Galen aneurysms than transarterial embolization or surgery.

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.

Long term follow-up of 43 pure dural arteriovenous fistulae (AVF) of the lateral sinus

ma: case report. Can J Neurol Sci 6:363-365 18. Mori K, Handa H, Murata T, Ishikawa M, Takeuchi J, Osaka K (1980) Craniopharyngiomas with unusual topography associated with vascular pathology. Acta Neurochir (Wien) 53:53-68 19. Matthews FD (1983) Intraventricular craniopharyngioma. AJNR 4:984-985 20. Grover WD, Rorke LB (1968) lnvasive craniopharyngioma. J Neurol Neurosurg Psychiatry 31 : 580-582 21. Mordson G, Sobel DF, Kelley WM, Norman D (1984) Intraventricular mass lesions. Radiology 153:435-442 22. Lanzieri CF, Sacher M, Som PM (1985) CT changes in the septum pellucidum associated with intraventricular craniopharyngiomas. J Comput Assist Tomogr 9:507-510 23. Ravindran M, Radhakrishnan VV, Rao VRK (1980) Communicating cystic craniopharyngioma. Surg Neurol 14:230-232 24. Braun IF, Pinto RS, Epstein F (1982) Dense cystic craniopharyngiomas. AJNR 3:139-141 473

Arterial distribution of calibrated tris-acryl gelatin and polyvinyl alcohol microspheres in a sheep kidney model.

Objective:The objective of this study was to compare the repartition in the renal arterial vasculature of tris-acryl gelatin microspheres (TGMS) and polyvinyl alcohol microspheres (PVAMS) of 3 calibers (500–700, 700–900, and 900–1200 μm). Materials and Methods:Twelve kidneys from 6 adult sheep were embolized and histologically analyzed. The number and size of microspheres and vessels were measured, as well as the deformation of TGMS and PVAMS, and the histologic location according to a classification in 5 zones of the kidney. Results:Two hundred eighty-four vessels were measured. The diameter of the occluded vessels increased when the caliber used for embolization was larger for TGMS and for PVAMS (P < 0.0001, each). The location of TGMS and PVAMS within the vasculature was different for each caliber, because PVAMS blocked significantly more distally than TGMS (P < 0.0001 each). The deformation within the tissue was greater for PVAMS (18.0 ± 12.3%) than for TGMS (9.0 ± 8.3%) in general (P < 0.001) and for each caliber of injected microspheres (P < 0.001 each). Conclusion:The repartition of a spherical embolic agent in a given vascular network can be influenced by its size and also by its deformation within the vascular bed.