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M Piotin

Publications and source records attributed to M Piotin.

At least 37 records · Page 2Linked to original sources
PubMed2000

Percutaneous transluminal angioplasty and stenting of the proximal vertebral artery for symptomatic stenosis.

BACKGROUND AND PURPOSE: Percutaneous transluminal angioplasty (PTA) for significant stenosis involving the origin of the vertebral artery is now a well established treatment for selected patients when posterior cerebral arterial circulation is compromised. Arterial spasm, dissection, and restenosis may occur in some instances, with subsequent hemodynamic compromise. To prevent these potential complications, we combined PTA of the vertebral artery with primary stenting, using coronary stents, in seven patients. We herein present our short- and intermediate-term results. METHODS: A total of seven lesions affecting the origin of the vertebral artery were treated by primary trans-stenotic coronary stent placement. All patients were symptomatic, fulfilling the general criteria for vertebral artery angioplasty. Patients were followed for up to 36 months after treatment. RESULTS: All seven lesions were successfully dilated. Residual stenosis was never greater than 20% in diameter. No perioperative complications occurred. Clinical follow-up showed immediate resolution or improvement of symptoms in all patients. One patient's condition deteriorated 15 months after stent placement because of atheromatous stenosis of the prevertebral segment in the ipsilateral subclavian artery. CONCLUSION: Stent placement to treat significant stenosis involving the origin of the vertebral artery is safe and effective for alleviating symptoms and improving blood flow to the posterior cerebral circulation. Coronary stent design seems to be particularly well suited to cover atherosclerotic lesions of the origin of the vertebral artery. The stent mesh probably prevents elastic recoil and early restenosis after PTA, as it does in coronary arteries.

Aged↗
PubMed2000

Dense packing of cerebral aneurysms: an in vitro study with detachable platinum coils.

Aneurysm models were used to study the density of packing after coil embolization. Platinum coils were introduced until the point of minimally dense packing, indicated by aneurysmal circulatory exclusion. Packing was continued up to the point of maximal density, indicated by protrusion into the parent artery. Volumetric ratios (coil volume/aneurysmal volume) were calculated for minimally and maximally dense packing. Maximally dense packing ratios were a little higher than the minimally dense ratios, but less than 37%.

Implants, Experimental↗
PubMed1999

The various MRI patterns of pituitary apoplexy.

The aim of this study was to describe the various MRI features, in correlation to surgical and pathological findings, in patients who presented with pituitary apoplexy (PA). Eleven patients presenting with PA, were evaluated with various MR protocols including spin-echo (SE) T1-weighted sequences in 9 of 11 patients, post gadolinium SE T1-weighted sequences in only 8 of 11 patients, and with T2-weighted SE sequences in 2 of 11 patients. All patients had transsphenoidal pituitary surgery after MR studies. The severity of presenting symptoms ranged from headaches to coma. Ten patients had pituitary macroadenoma; one had a non-hemorrhagic metastatic lesion into a non-adenomatous pituitary gland. Of the 11 patients, one was studied at the acute stage of PA (1 day after onset), 9 at the subacute period (3-15 days after onset), and one at the late stage (5 months after onset). Images compatible with intratumoral hemorrhage were found in all macroadenomas, whereas the metastatic pituitary lesion did not show evidence of bleeding. All gadolinium-enhanced studies showed partial tumoral enhancement. The SE T2-weighted studies demonstrated areas of low and high signal intensities in keeping with the presence of blood degradation contents. Pituitary apoplexy present with different MR features, including hemorrhagic and non-hemorrhagic characteristics on T1-weighted images. Gadolinium-enhanced images do not provide complementary diagnostic information when the presence of blood is assessed on plain images.

Adult↗
PubMed1999

Vertebroplasty: clinical experience and follow-up results.

This study was undertaken to report the clinical experience with percutaneous minimal invasive vertebroplasty using polymethyl-methacrylcate (PMMA) for a consecutive group of patients. Over the period of the last 4 years, 40 patients were treated at 68 vertebral segment levels with the intention to relieve pain related to vertebral body lesions. Reduced vertebral body height and destruction of the posterior vertebral wall were not considered to be exclusion criterias. The vertebroplasty procedure was performed under general anesthesia and in prone position with imaging control using mostly biplane DSA fluoroscopic guidance, and rarely with single-plane mobile DSA combined with computed tomographic guidance. Unilateral, but more frequently bilateral, transpedicular introduction of a 2-3-mm OD needle was followed by an injection of polymethyl-methacrylcate (PMMA). PMMA preparation involved a diluted mixture (20 mL powder for 5 mL liquid) allowing for an extended polymerization time of up to 8 min. The PMMA was mixed with metallic powder to enhance its radio-opacity. Before PMMA injection, a vertebral phlebography was obtained to evaluate the filling pattern and identify sites of potential PMMA leakage. Injection of opacified PMMA was performed under continuous visual control with fluoroscopy to obtain adequate filling and to avoid important PMMA leakage. Clinical follow-up involved an evaluation using a questionnaire for assessment of pain, pain medication, and mobility. One to six levels were treated in one to three treatment sessions for patients with metastatic, osteoporotic, and hemangiomatous lesions of the vertebral bodies who presented with pain. The results observed matched those reported previously with a success rate of approximately 80% and a complication rate below 6% per treated level. Treatment failure and complications observed were related to leakage, insufficient pretreatment evaluation, anesthesia, or patient position during treatment. Image guidance with fluoroscopy was efficient both for precise transpedicular approach and PMMA implantation control. Vertebroplasty is very efficient for treatment of pain. Treatment failure was mostly related to insufficient pretreatment clinical evaluation, and complication due to excessive PMMA volume injection. Control of PMMA volume seems to be the most critical point for avoiding complications. A good fluoroscopy control is therefore mandatory.

Adult↗
PubMed1999

Long-term angiographic follow-up of 169 intracranial berry aneurysms occluded with detachable coils.

PURPOSE: To evaluate the stability of aneurysm occlusion at follow-up angiography after endovascular treatment (EVT) with detachable coils in intracranial berry aneurysms. MATERIALS AND METHODS: A total of 203 berry aneurysms (< 1.5 cm) were treated with EVT. Follow-up angiography at least 3 months later was performed in 169 cases. RESULTS: Complete occlusion of the aneurysm sac and neck was achieved in 148 aneurysms, subtotal occlusion in 18, and incomplete occlusion in three. Recurrence occurred between 3 and 40 months in 20 (14%) of the 148 totally occluded aneurysms. A second treatment was performed in five cases, was scheduled in one, and failed in one. The small neck remnant increased in size but did not require any retreatment in three cases, and the size of the neck remnant remained stable in 10 cases. Remnant regrowth occurred in six of the 18 subtotally occluded aneurysms. A second treatment was performed in three. Of the 169 cases, last follow-up angiography showed total occlusion in 133 cases, subtotal in 30, and incomplete in six. No rebleeding occurred. CONCLUSION: A very small recurrence may be observed at the level of the neck of the aneurysm at long-term follow-up angiography despite achieving total occlusion initially with detachable coils.

Cerebral Angiography↗
PubMed1999

In vitro models of intracranial arteriovenous fistulas for the evaluation of new endovascular treatment materials.

BACKGROUND AND PURPOSE: The purpose of this study was to create and test an in vitro model of intracranial arteriovenous fistulas (AVFs) that simulates the geometry of human vasculature and allows realistic testing of devices used in endovascular therapy. METHODS: The models were derived from corrosion casts of the main cervicocranial arteries and veins obtained from two nonfixed human specimens. Wax copies of the casts were produced and combined to create complex models simulating various types of intracranial AVFs. Wax assemblies were embedded with liquid silicone solidified into transparent blocks containing, after wax evacuation, hollow reproductions of the original vascular trees. The models were connected to a pulsatile pump and their compatibility with various imaging techniques and endovascular treatment materials was evaluated. RESULTS: The models were compatible with digital subtraction angiography, CT, MR imaging, and transcranial Doppler sonography. They provided a realistic endovascular environment for the simulation of interventional neuroradiologic procedures. CONCLUSION: Anatomically accurate and reproducible in vitro models of intracranial AVFs provide a valuable method for evaluating new endovascular treatment materials and for teaching purposes.

Aged↗
PubMed1999

[Endovascular treatment of intracranial aneurysms].

Over recent years, an increasing number of patients with intracranial aneurysms are treated by endovascular techniques, which have the advantage of avoiding craniotomy and retraction of cerebral parenchyma, while reducing the postoperative hospital stay. The key concept is that aneurysm is a disease of the arterial wall and that treatment must ideally only concern the vessel. The short-term efficacy of endovascular treatment has been established, especially for the prevention of early rebleeding, but its long-term efficacy has not yet been formally demonstrated due insufficient follow-up. Ideally, the management of intracranial aneurysms should be based on close collaboration between neurosurgeons and interventional neuroradiologists and the approach (conventional surgery or endovascular) should be discussed case by case.

Aftercare↗
PubMed1998

Epidermoid cyst of the skull with nonpulsatile tinnitus.

We report an intradiploic epidermoid cyst of the skull responsible for transverse sinus compression and presenting with nonpulsatile tinnitus. Plain films and CT both demonstrated the tumour. Cerebral angiography showed best the degree of narrowing of the right transverse sinus, accompanied with turbulent flow probably leading to tinnitus. MRI demonstrated accurately both the tumour and the dural sinus compression. The tumour was totally removed, cranioplasty was performed, and the patient was discharged free of symptoms.

Adult↗
PubMed1998

Second-generation three-dimensional reconstruction for rotational three-dimensional angiography.

RATIONALE AND OBJECTIVES: The purpose of this study was to assess the feasibility and accuracy of three-dimensional (3D) reconstruction techniques for digital subtraction angiography (DSA) in planning and evaluation of minimally invasive image-controlled therapy. MATERIALS AND METHODS: Using a standard, commercially available system, the authors acquired DSA images and corrected them for inherent distortions. They designed and implemented parallel and multiresolution versions of cone-beam reconstruction techniques to reconstruct high-resolution targeted volumes in a short period of time. Testing was performed on anatomically correct, calibrated in vitro models of a cerebral aneurysm. These models were used with a pulsatile circulation circuit to allow for blood flow simulation during DSA, computed tomographic (CT) angiography, and magnetic resonance (MR) angiography image acquisitions. RESULTS: The multiresolution DSA-based reconstruction protocol and its implementation allowed the authors to achieve reconstruction times and levels of accuracy for the volume measurement of the aneurysmal cavities that were considered compatible with actual clinical practice. Comparison with data obtained from other imaging modalities shows that, besides vascular tree depiction, the DSA-based true 3D technique provides volume estimates at least as good as those obtained from CT and MR angiography. CONCLUSION: The authors demonstrated the feasibility and potential of true 3D reconstruction for angiographic imaging with DSA. On the basis of the model testing, this work addresses both the timing and quantification required to support minimally invasive image-controlled therapy.

Algorithms↗
PubMed1998

[Intracranial dural arteriovenous fistula with perimedullary venous drainage].

Two cases of intracranial dural arterio-venous fistula (DAVF) with perimedullary venous drainage are reported. In both cases, MRI T2-weighted (T2W) images showed an hypersignal within the cervical cord with sparing of the thoracic cord. In one case perimedullary vessels were demonstrated on T1W images after gadolinium i.v. administration. A complete spinal angiogram did not show evidence of fistula but demonstrated the lack of opacification of the conus medullaris venous drainage. Cerebral angiogram demonstrated in the first case a foramen magnum DAVF and in the second case a petrous apex DAVF. Hypersignal limited to the cervical cord at MRI on T2W images remain exceptionnal in case of intracranial DAVF with perimedullary venous drainage. When neurological symptoms are suggestive, post gadolinium T1W sequences should be conducted, followed by selective spinal angiogram. If normal venous drainage is not objectivated (e.g. opacification of radiculo-medullary veins on the late phase), cerebral angiogram should be done to rule out an intracranial DAVF.

Aged↗
PubMed1997

An in vitro anatomic model of the human cerebral arteries with saccular arterial aneurysms.

An in vitro model of the main human cerebral arteries with or without saccular arterial aneurysms is presented. A cast of the cerebral arteries was obtained in a human specimen. Three aneurysms were simulated and added to the cast. Wax copies of the cast were produced, and embedded with liquid resin solidifying into solid blocks. After evacuation of the wax, a model consisting of a hollow reproduction of the cast within the resin block was obtained. The model is reproducible and anatomically accurate. Since it is transparent to visible light, and compatible with x-ray, magnetic resonance and transcranial doppler techniques, it should prove useful for a wide range of haemodynamic and radiologic investigations. The reported technique may be adapted to any structure with a hollow configuration, allowing for the preparation of arterial and venous models from other vascular areas, as well as models from other anatomic systems, such as the biliary or urinary tracts.

Cerebral Arteries↗
PubMed1996

MRI and MR angiography of persistent trigeminal artery.

We describe the MRA and MR angiography (MRA) features of persistent trigeminal artery (PTA) found incidentally in eight patients, with special attention to its origin, site and course. The different patterns of posterior communicating arteries were also noted. The PTA were shown on sagittal, coronal and axial MRI and on MRA. In four cases, the PTA arose from the lateral aspect of the intracavernous internal carotid artery, ran caudally, passing round the bottom of the dorsum sellae to join the basilar artery. In the other four cases, it arose from the medial aspect, ran caudally through the sella turcica and pierced the dorsum sellae to join the basilar artery. The posterior communicating arteries were present unilaterally in five cases and bilaterally in one, and absent bilaterally in two. Identification of a PTA with a trans-sellar course is crucial if a trans-sphenoidal surgery is planned.

Adolescent↗
PubMed1996

Early CT signs in acute middle cerebral artery infarction: predictive value for subsequent infarct locations and outcome.

During the first hours after acute ischemic stroke, the CT usually shows no abnormalities. Therapeutic trials of ischemia in the middle cerebral artery (MCA) territory involves decision-making when the CT may not show obvious ischemic changes. We reviewed 100 consecutive patients, admitted within 14 hours after a first stroke. Selective criteria were clinical presentation with MCA ischemia and at least two CTs (1 initial and 1 control). All CTs were retrospectively analyzed by at least two physicians blinded to the patient's status. On the first CT, early signs were hyperdense MCA sign (HMCAS), early parenchymatous signs (attenuation of the lentiform nucleus [ALN], loss of the insular ribbon [LIR], and hemispheric sulcus effacement [HSE]), midline shift, and early infarction. Subsequent infarct locations were classified according to total, partial superficial (superior or inferior), deep, or multiple MCA territories. Clinical features, etiology, and Rankin scale were collected. There were 52 women (mean age 70.8). The CTs were performed at mean 6.4 hours (1 to 14 hours) and before the sixth hour in 62% of the patients. Early CT was abnormal in 94% of the cases, and the abnormalities found were an HMCAS in 22 patients, ALN in 48, LIR in 59, HSE in 69, midline shift in 5, and early infarct in 7. CT was normal in six patients where it was performed earliest (mean 4.5 hours) and in the oldest patients (mean age 80.1). Early parenchymatous CT signs were significantly associated with subsequent MCA infarct location and extension: ALN and deep infarct, HSE and superficial infarct, LIR and large infarct. HMCAS was never found in isolation and was always associated with the three other signs in extended MCA infarct. The presence of two or three signs (ALN, LIR, or HSE) was associated with extended MCA infarct (p < 0.001) and poor outcome (p < 0.001). Our findings suggest that CT frequently discloses parenchymal abnormalities during the first hours of ischemic stroke. Early signs allow the prediction of subsequent infarct locations; CT may provide a simple tool in evaluating the early prognosis of MCA infarction and thus may be useful in selecting better treatments.

Adult↗
PubMed1995

Percutaneous transcatheter embolization in multiply injured patients with pelvic ring disruption associated with severe haemorrhage and coagulopathy.

Six multiply injured patients with pelvic fractures were treated by percutaneous transcatheter embolization during a 10 month period. Diagnosis and therapy were carried out early in two cases (first day of admission into the trauma unit). Three patients were treated on the second day after admission. The last patient was embolized on the third day. Two patients underwent one and two remote embolizations. Embolization was indicated due to uncontrolled haemorrhaging, requiring large volumes of packed erythrocytes (median: 11.3) and fresh frozen plasma units (median: 6.8). Three patients had severe coagulopathy (disseminated intravascular coagulation). From two to 12 arteries were embolized per patient (median: 5). After successful transcatheter embolization, the circulation and coagulation stabilized rapidly without recurrence of haemorrhage or coagulopathy.

Adult↗
PubMed1994

Postoperative pseudoaneurysm of ascending aorta: role of ultrafast computed tomography imaging.

A 34-year-old woman, who had undergone a thoracic aortic aneurysmectomy and replacement with a prosthetic tube graft several months previously, presented with a pseudoaneurysm arising from the proximal anastomotic site. This pseudoaneurysm was studied with contrast-enhanced ultrasfast computed tomography. The exact location of the suture dehiscence was located by the presence of a contrast jet flow through the aortic wall. This case shows the feasibility of demonstrating blood flow at the entry site of a pseudoaneurysm with ultrafast computed tomography which may avoid conventional angiography.

Adult↗