José M. Carreira

Treatment of Chronic Iliac Artery Occlusions with Guide Wire Recanalization and Primary Stent Placement

PURPOSE To evaluate the results of primary stent placement without initial thrombolysis in the treatment of iliac occlusions. MATERIALS AND METHODS During a 3-year period, 61 iliac artery occlusions were treated in 59 patients. The mean length of the occluded segment was 10 cm (range, 4-25 cm). The occluded arteries were treated with primary placement of self-expandable metallic stents. RESULTS Successful recanalization with primary stent placement was possible in 56 of 61 occlusions (92% technical success rate). Mean Doppler ankle/brachial index increased from 0.51 to 0.90 immediately after treatment and was 0.91 on the last follow-up (P < .05). Primary patency rate at 24 months was 73%, and secondary patency rate was 88%. Procedural complications included distal embolization (n = 4) and an episode of massive intra-abdominal bleeding. Three patients developed a hematoma at the puncture site that did not require additional therapy. Late complications included stent occlusion (n = 9) and significant stenosis related to intimal hyperplasia (n = 1). Mean follow-up period was 29 months (range, 7-55 months). CONCLUSION Primary stent placement is an effective therapeutic option for iliac artery occlusions.

Treatment of Complete and Partial Obstruction of the Nasolacrimal System with Polyurethane Stents: Initial Experience

AbstractPurpose: To present our experience in the treatment of nasolacrimal occlusion by means of polyurethane stents. Methods: Forty polyurethane stents were placed under fluoroscopic guidance in 35 consecutive patients with epiphora due to total or partial obstruction of the nasolacrimal system. The set designed by Song was used in all patients. The procedure was performed by introducing a guidewire through the superior punctum into the canaliculus and advancing it across the obstruction into the inferior meatus of the nasal cavity. After pulling out the guidewire, the stent was advanced in retrograde fashion and released into the sac and the nasolacrimal duct. Results: The technical success rate was 100%. The average time for the procedure was 25 min (range 10–60 min). Immediate complications were: mild pain (n= 5), severe pain (n= 1), minimal epistaxis (n= 7), and moderate epistaxis (n= 1). No major complications occurred. The last clinical control revealed complete resolution of epiphora in 35 eyes and partial resolution in four; one patient did not improve. Conclusion: This technique for treatment of obstruction of the nasolacrimal system is simple and safe, and may obviate the use of more invasive procedures.

Intramuscular low flow vascular malformations: treatment by means of direct percutaneous embolization

PURPOSE Intramuscular hemodynamically inactive vascular malformations are infrequent entities whose surgical treatment is often impossible, crippling, or inefficient. We describe a nonsurgical therapeutic approach consisting on embolization by direct puncture with sclerosant substances. METHODS Four patients have been treated from April to November 1994, three female and one male, ranging in age from 13 to 31 years. Three vascular malformations were located in the quadriceps and one in the deltoid muscle. The point of access was determined with information provided by MR. The skin was cleaned with an antiseptic solution and puncture was performed with a 22 gauge Chiva needle. Blood flow inside the malformation was slow in all cases and no afference to the normal venous system was detected. We embolized with 5-15 cc (mean 7.5 cc) of a mixture of ethibloc and ethanol. RESULTS The mean follow-up period was 17 months (range 14-21). All patients remain asymptomatic and have resumed normal daily life activities. There were no complications. CONCLUSION Percutaneous embolization by direct puncture of intramuscular vascular malformations is a feasible and simple procedure. Our preliminary results are promising, although more extensive studies need to be to performed in order to reach definite conclusions.

Endovascular treatment of an acutely ruptured intracranial aneurysm in pregnancy: report of eight cases

Treatment of acutely ruptured intracranial aneurysms in pregnancy represents a clinical challenge requiring a meticulously selected strategy. We report eight cases of ruptured cerebral aneurysms in eight pregnant patients treated safely and effectively via an endovascular approach.

Tratamiento percutáneo de las malformaciones vasculares periféricas con una mezcla de polidocanol y CO 2 . Experiencia inicial

Objetivo El tratamiento percutaneo de las malformaciones vasculares perifericas es hoy dia aceptado como primera opcion terapeutica en estos procesos. Describimos nuestra experiencia inicial con una mezcla de polidocanol y CO2 como agente embolizante, analizando su eficacia y complicaciones. Material y metodos Entre abril de 2005 y diciembre de 2006 se han tratado 18 pacientes, 11 mujeres (61%) y 7 hombres (39%) con edades comprendidas entre 11 y 80 anos. Una malformacion vascular era hemodinamicamente activa (5%) y 17 eran hemodinamicamente inactivas (95%). Se realizaron en total 56 embolizaciones (rango: 1-7; media: 3) con una mezcla de polidocanol y CO2 (rango: 1-28 cm3; media 8 cm3). Las malformaciones se estudiaron con ecografia-Doppler, resonancia magnetica y angiografia por puncion directa o arteriografia. En funcion de la localizacion, tamano y caracteristicas hemodinamicas, se realizaron abordajes y tratamientos especificos para cada caso. Resultados Se obtuvo un exito tecnico, entendiendo como tal la posibilidad de embolizar la malformacion en el 100% de los casos. No se produjeron complicaciones tecnicas. El periodo medio de seguimiento fue de 9 meses (rango: 1-20). Todos los pacientes, excepto una que rechazo continuar con el tratamiento, mejoraron objetiva y subjetivamente, y todos recuperaron las actividades diarias normales. Todos los pacientes presentaron edema, dolor e incremento de su impotencia funcional tras la embolizacion, que cedieron con tratamiento medico. Conclusion La embolizacion percutanea de malformaciones vasculares con una mezcla de polidocanol y CO2 es un metodo eficaz y con baja incidencia de complicaciones. Nuestros resultados iniciales son esperanzadores, aunque se precisan estudios mas extensos para extraer conclusiones definitivas.

Semi-automatic segmentation and detection of aorta dissection wall in MDCT angiography.

Aorta dissection is a serious vascular disease produced by a rupture of the tunica intima of the vessel wall that can be lethal to the patient. The related diagnosis is strongly based on images, where the multi-detector CT is the most generally used modality. We aim at developing a semi-automatic segmentation tool for aorta dissections, which will isolate the dissection (or flap) from the rest of the vascular structure. The proposed method is based on different stages, the first one being the semi-automatic extraction of the aorta centerline and its main branches, allowing an subsequent automatic segmentation of the outer wall of the aorta, based on a geodesic level set framework. This segmentation is then followed by an extraction the center of the dissected wall as a 3D mesh using an original algorithm based on the zero crossing of two vector fields. Our method has been applied to five datasets from three patients with chronic aortic dissection. The comparison with manually segmented dissections shows an average absolute distance value of about half a voxel. We believe that the proposed method, which tries to solve a problem that has attracted little attention to the medical image processing community, provides a new and interesting tool to isolate the intimal flap that can provide very useful information to the clinician.

Long‐term follow‐up of Symphony nitinol stents in iliac arteriosclerosis obliterans

The purpose of this study was to evaluate the long‐term results of iliac artery stent placement with use of the symphony stent for the treatment of patients with intermittent claudication. In a prospective study, 31 cases of iliac occlusive arterial disease were treated in 26 patients. Stenoses (n = 27) were treated after failed angioplasty, and occlusions (n = 4) were treated with primary stent placement. Clinical history, clinical stage and the ankle brachial‐index (ABI) examination measurement were assessed. The patients were followed up with clinical examination, ABI examination measurement and intravenous angiography. The follow‐up period ranged between 9.5 months and 7.5 years (median = 5.9 yr). Data were analyzed using the univariate analysis (Kaplan‐Meier method). The mean±SD ABI pre‐, post‐procedure and in the last control was 0.70±0.17, 0.97±0.15, and 0.96±0.20, respectively. Primary patency rates (%) ± SE were 83±7 after 3 years, 75±8 after five years, and 67±9 after seven years, and secondary patency rates were 93±5 after three years, 86±7 after five years, and 86±7 after seven years. During the first 24 hours, one patient presented occlusion of the treated segment. During follow‐up, 9 (29%) patients were admitted to our hospital because of worsening of the symptoms. In this study, the symphony stent has been proven to be a good device to treat lesions in the iliac region but more experience is needed to optimize endovascular treatment in this area. In our experience the treatment of iliac artery occlusive disease with symphony stents can be considered a good option with acceptable patency rates and low morbidity and mortality.

Utilidad del gadolinio como medio de contraste en procedimientos terapéuticos endovasculares

Objetivo Valorar la utilidad del gadolinio asociado al CO2 como medio de contraste angiografico para la realizacion de procedimientos terapeuticos endovasculares en pacientes que presentan alteracion de la funcion renal. Material y metodos Desde enero del 2000 a junio del 2001 se realizaron 10 tratamientos endovasculares usando CO2 y gadolinio como medio de contraste en pacientes con deterioro de la funcion renal (creatinina > 1,5 mg/ml). Resultados La dosis media de gadolinio administrada fue 42 ml. En todos los casos las imagenes diagnosticas o terapeuticas fueron satisfactorias. No se detectaron incrementos significativos entre los valores de urea y creatinina previos y los obtenidos a las 24, 48 y 72 horas despues del procedimiento. Conclusion El gadolinio es un medio de contraste util en combinacion con CO2 para la realizacion de procedimientos terapeuticos endovasculares en pacientes con deterioro de la funcion renal.

CO2 as a contrast medium in endoluminal treatment of high flow vascular malformations

PURPOSE To evaluate the diagnostic usefulness of CO2 as a radiologic contrast medium in pre and post-embolization of hemodynamically active vascular malformations. MATERIAL AND METHODS Eight pre-and post-embolization angiographies were performed on five patients with hemodynamically active vascular malformations. In all cases sequentially iodinated contrast medium and CO2 were used. Procedures were performed using Philips Integris V equipped with specific software to process images obtained with CO2 as contrast medium and with a purpose-built gas injector pump. The images were assessed by three interventional radiologists who evaluated the findings by consensus. They were asked whether uptake of the malformations were better, worse or the same with iodinated contrast and CO2. The images were judged according to the following characteristics; quality, the filling in of the contrast in afferent artery of the HAVM, caliber and number of vessels and existence of pathologic communications in HAVM. These characteristics were assessed in all the patients of the study, both before and after embolization. RESULTS The CO2 angiographic results were compared to those obtained using iodinated contrast material. Iodinated contrast provided superior image quality in all performed studies. The filling of arterial afference of HAVM was well defined with both contrast media. In all performed cases with CO2, the malformations showed more vessels. No inmediate nor subsequent complications developed with CO2 injections, except in one female patient, who presented an intense sensation of cramps in the lower limbs. CONCLUSION CO2 is a useful diagnostic and assessment tool before and especially during the embolization of hemodynamically active vascular malformations. It improves quantification and uptake of the malformations vascular architecture, detecting collateral circulation and arteriovenous shunts. It also detects residual post-embolization disease when iodinated contrast agent is unsuccessful.

Robust Detection of Circles in the Vessel Contours and Application to Local Probability Density Estimation

In this work we propose a technique to automatically estimate circular cross-sections of the vessels in CT scans. First, a circular contour is extracted for each slice of the CT by using the Hough transform. Afterward, the locations of the circles are optimized by means of a parametric snake model, and those circles which best fit the contours of the vessels are selected by applying a robust quality criterion. Finally, this collection of circles is used to estimate the local probability density functions of the image intensity inside and outside the vessels. We present a large variety of experiments on CT scans which show the reliability of the proposed method.