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Biomedical subjects

J J Merland

Publications and source records attributed to J J Merland.

At least 289 records · Page 16Linked to original sources
PubMedDate not supplied

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.

Aneurysm↗
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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.

Adolescent↗
PubMedDate not supplied

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.

Adolescent↗
PubMedDate not supplied

Biocompatibility of 1-French polyethylene catheters used in interventional neuroradiology procedures: a study with rats and dogs.

This study was designed to investigate the thrombogenicity, inflammatory response, and endothelial response to the presence of sterilized, 1-French polyethylene catheters implanted into the arterial system and subcutaneous tissues of 18 rats and two dogs. At time periods ranging from 1 week to 6 months, repeat angiography was done, the animals sacrificed, and the tissues containing the catheter removed for histologic study. In the subcutaneous tissues the catheter became encased in a very thin (less than 0.5 mm) coating of fibrous tissue with no evidence of inflammation. In large vessels, the catheter at all time periods appeared identical both angiographically and histologically to that at the time of implantation. In small to medium-sized vessels a slight increase in vessel size (25% increase in diameter of the rat iliac) was observed angiographically. On histologic evaluation, there was evidence of myointimal hypertrophy, which was asymmetrically placed, centered around the position of the catheter. There was no evidence of thrombi or of incorporation of the catheter itself into the hypertrophic tissue. In dogs and rats, an implanted 1-French polyethylene catheter is well tolerated: the animals showed no evidence of thrombotic, thromboembolic, or inflammatory complications. Myointimal hypertrophy was observed in small to medium-sized arteries, which is of unknown significance.

Animals↗
PubMedDate not supplied

Classification of spinal cord vascular malformations.

Through the aid of developments in the neuroradiological sciences, great attention has been given to the diagnosis and treatment of vascular malformations of the spinal cord. Some of these are congenital, such as intramedullary vascular malformations and arteriovenous fistulae supplied by the spinal cord. Others are rather frequent and appear in old age. Due to their poor prognosis when not treated, precise determinations and sufficient knowledge are of the utmost importance.

Aged↗
PubMedDate not supplied

[Bilateral nephrectomy by embolization of the renal arteries: a report on five cases (author's transl)].

Selective bilateral renal artery embolization was performed in 5 patients because of severe hypertension not responding to conventional medical treatment, in two patients on repeated dialysis; severe nephrotic syndromes with chronic renal insufficiency in the three other patients. A significant drop in blood pressure occurred in only two of the hypertensive patients, about 40 days after embolization. Bilateral surgical nephrectomy was required in the other patient because of persistence of residual vascularization and high RAP. Excellent results were obtained in the 3 patients with a nephrotic syndrome, with disappearance of proteinuria and anuria following the embolization. For this method to be effective, the arterial obliteration has to be complete and definitive. When symptoms persist or there is a relapse, especially in the cases with hypertension, a repeated arteriographic examination and complementary embolization has to be envisaged. Further experience with this method is necessary in order to compare the results with those obtained after bilateral surgical nephrectomy. Medical treatment with agents toxic to the tubules, in cases of the nephrotic syndrome, has apparently not produced the results expected. The relative simplicity of this embolization procedure has to be underlined, together with the fact that it is free from major complications when performed by surgeons trained in its use, on the condition that purification be carried out immediately following embolization.

Adult↗
PubMedDate not supplied

[Angiodysplasia or vascular malformations of the cervical spine (author's transl)].

Following exploration by angiography , 45 patients with cervical spine malformations ( out of 220 cervicocephalic examinations for vascular malformations), were treated by embolization. The 45 cases included 13 facial lesions, 4 pharyngolaryngeal lesions, 2 cervical venous ectasias, 4 arteriovenous fistulae of the vertebral artery, 19 medullary lesions, and 3 pseudomalformations (hemangiopericytomas). Though embolization is difficult it is of value in definitely vascular occlusions (follow-up for 3 years), and miniaturization of catheters and balloon sounds enables very selective occlusion of vascular tumors or malformations to be carried out, micro-emboli of 30 to 500 mu have been obtained.

Arteriovenous Fistula↗
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[Congenital arterio-venous malformations. Long-term therapeutic effects of arterial ligatures. A plea for their abandon in favour of more recent procedures (author's transl)].

It is well known that proximal arterial ligations have no curative effect on arterio-venous malformations, unfortunately however they are still employed. The immediate and late consequences of such ligatures have been studied by analysing 36 out of 142 cases of arterio-venous malformations. These ligatures interfere with ulterior treatment. At present such a treatment relies on a combination of radio-surgical treatment associated with embolization and complete surgical excision of the malformation, whenever it is possible.

Arteries↗
PubMedDate not supplied

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.

Angiography↗
PubMedDate not supplied

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.

Adult↗