Marcelo Guimaraes

Predictive factors for the development of type II endoleaks.

Purpose To define predictive factors for endoleak type II (EL-II) based on quantifiable factors in the imaging studies of patients undergoing endovascular aneurysm repair (EVAR). Methods The data on 208 consecutive patients (137 men; mean age 75.2 years, range 62–84) who underwent EVAR between the years 2003 and 2008 were retrospectively reviewed. The abdominal aortic aneurysm (AAA) diameter ranged from 4.8 to 12.8 cm. Data were collected on the type of AAA; the type of stent-graft (aortomonoiliac versus bifurcated); the performance of hypogastric artery embolization; the presence, number, diameter, and patency of aortoiliac branches identified on the pre and post-EVAR imaging studies; and the presence and type of EL-II (transient vs. persistent) with the goal of identifying any imaging-based predictive factors for the development of EL-II. Results Among the 208 cases, 11 patients had endoleaks other than type II and were excluded, leaving 195 patients for analysis. In all, 28 (13.4%) patients were diagnosed with EL-II. All had ≥4 patent lumbar arteries (mean diameter >2.3 mm). Ten patients with a transient EL-II had a mean of 4.3 patent lumbar arteries, which had diameters <2 mm (mean 1.5 mm). In the 18 patients with persistent EL-II, the mean diameter of the 4 lumbar arteries was 2.7 mm; at least 1 of the lumbar arteries was >2 mm. The presence of at least 4 patent lumbar arteries (p<0.001) and at least 1 patent hypogastric artery (p<0.001) were predictive factors for EL-II. At least 1 lumbar artery >2 mm in diameter was a positive predictive factor for the development of persistent EL-II (p<0.001). Conclusion Patent hypogastric and lumbar arteries are significantly associated with a higher risk of developing EL-II. Larger diameter lumbar arteries tend to be associated with persistent EL-IIs, while lumbar arteries <2 mm would more likely be seen with a transient EL-II. If substantiated in larger studies, these angiographic criteria may guide early treatment of EL-II to avoid aneurysm sac expansion and potential rupture.

Radiofrequency Wire for the Recanalization of Central Vein Occlusions that Have Failed Conventional Endovascular Techniques

PURPOSE To report the technique and acute technical results associated with the PowerWire Radiofrequency (RF) Guidewire used to recanalize central vein occlusions (CVOs) after the failure of conventional endovascular techniques. MATERIALS AND METHODS A retrospective study was conducted from January 2008 to December 2011, which identified all patients with CVOs who underwent treatment with a novel RF guide wire. Forty-two symptomatic patients (with swollen arm or superior vena cava [SVC] syndrome) underwent RF wire recanalization of 43 CVOs, which were then implanted with stents. The distribution of CVOs in central veins was as follows: six subclavian, 29 brachiocephalic, and eight SVC. All patients had a history of central venous catheter placement. Patients were monitored with regular clinical evaluations and central venography after treatment. RESULTS All 42 patients had successful recanalization of CVOs facilitated by the RF wire technique. There was one complication, which was not directly related to the RF wire: one case of cardiac tamponade attributed to balloon angioplasty after stent placement. Forty of 42 patients (95.2%) had patent stents and were asymptomatic at 6 and 9 months after treatment. CONCLUSIONS The present results suggest that the RF wire technique is a safe and efficient alternative in the recanalization of symptomatic and chronic CVOs when conventional endovascular techniques have failed.

Onyx (Ethylene-vinyl Alcohol Copolymer) in Peripheral Applications

Onyx is a nonadhesive liquid embolic agent approved for the treatment of brain arteriovenous malformations. Here, the use of Onyx is discussed in different peripheral procedures. The Onyxs features, its manipulation, technical details, tips, and tricks are presented followed by illustrative cases.

Stent migration complicating treatment of inferior vena cava stenosis after orthotopic liver transplantation

A case of inferior vena cava (IVC) stenosis after orthotopic liver transplantation was treated with balloon angioplasty and Wallstent placement. There was stent migration into the right atrium (RA), and percutaneous removal of the stent was attempted without success. Open cardiac surgery was required for stent removal and repair of aortic/RA fistula. Months later, recurrent IVC stenosis was successfully treated with placement of large Z stents after additional failed surgical repair. At 2 years follow-up, the patient is asymptomatic and Doppler ultrasonography demonstrated the stent to be patent and well-positioned.

Stent-Graft Treatment of Pseudoaneurysms and Arteriovenous Fistulae in the Carotid Artery

The purpose of this study was to assess the safety and efficacy of stent-graft placement in the management of arteriovenous fistulae (AVF) and pseudoaneurysms (PAs) involving the carotid artery (CA). Twenty-two patients (16 men, 6 women) with a CA AVF (n = 5) or PA (n = 17) owing to a gunshot or stab wound, carotid endarterectomy, blunt trauma, a tumor, spontaneous dissection, or a central venous catheter were treated with percutaneous placement of stent grafts. The patients presented with tumor, bruit, headache, mouth and tracheostomy bleeding, transitory hemiparesis, seizure, or stroke. Diagnoses were made by using computed tomographic angiography (CTA) and digital subtraction angiography. Fourteen lesions were in the common CA; eight were in the internal CA. Homemade devices and stent grafts from a variety of manufacturers were employed. Follow-up evaluations included clinical, CTA, and Doppler ultrasound assessments. All patients had resolution of the PA or AVF. In one patient with a large petrous PA, acute occlusion of the CA developed after placement of three balloon-expandable stent grafts, but there were no neurologic complications because the circle of Willis was functional. During follow-up ranging from 2 months to 13 years, asymptomatic 90% stenosis owing to stent compression was observed on Doppler ultrasound and angiographic examinations in a patient with an autologous vein–covered stent graft in the internal CA. Three other patients died of causes unrelated to stent-graft placement. In all other patients, the stent graft remained patent. Our results indicate that stent grafting is an acceptable alternative to surgery in the treatment of AVF and PAs in the CA.

Successful Recanalization of Bile Duct Occlusion with a Radiofrequency Puncture Wire Technique

A radiofrequency (RF) wire puncture technique was used in the recanalization of biliary anastomotic occlusions in five patients. The technical success of recanalization, which was defined as successful puncture and crossing of the obstruction followed by balloon cholangioplasty and internal-external biliary drainage without evidence of complications, was 100%. The average follow-up was 13 months (range, 11-16 months). For biliary occlusion recanalization, the RF wire may allow the use of percutaneous therapy in the treatment of a subset of individuals who would otherwise have to undergo open surgical intervention.

Locoregional Therapy for Hepatocellular Carcinoma

Locoregional therapies for hepatocellular carcinoma have progressed greatly in the last 30 years, beginning with the introduction of chemoembolization. Embolization techniques have evolved with the use of drug-eluting beads and radioembolization with yttrium-90. In the last 10 years, several new ablation techniques were developed including radiofrequency ablation, microwave ablation, cryoablation, laser ablation, and irreversible electroporation. Isolated or in combination, these techniques have already shown that they can improve patient survival and/or provide acceptable palliation.

Percutaneous retrieval of an Amplatzer septal occluder device that had migrated to the aortic arch.

The secundum type atrial septal defect (ASD) is a relatively common finding in the general population, occurring at a reported rate of 3.78 per 100,000 live births [1], and comprising approximately 6–10% of all congenital cardiac defects [2]. When faced with a symptomatic ASD, there are several methods of treatment available. Open surgery with occlusion of the ASD is the time-honored treatment [3], but percutaneous placement of an occluder device has been the preferred treatment for several years [4]. The choice for the closure method is mainly based on the severity of symptoms, the underlying medical condition, cardiovascular anatomy [5, 6], and the size of the septal defect [7]. Surgical repair has been practiced for more than 50 years and often is preferred when the ASD size is larger and the symptoms are more severe [3]. However, percutaneous occluder device placement has largely replaced surgery when the patient is incapable of withstanding a major procedure, when the septal defect is\24 mm [8], and when the septal defect is not located near other vital cardiovascular structures [6]. The Amplatzer septal occluder (ASO) device has been extensively studied for the percutaneous closure of both ventricular as well as atrial septal defects [9, 10]. Using the approach first described in 1976 by King and Mills [4], the Amplatzer device can be placed via a venous route, and may be secured without placing the patient under general anesthesia or using cardiopulmonary bypass. Although percutaneous device placement has been found to have a lower rate of overall complications than surgical closure [5], there have been several reports of adverse events in the literature [5, 6, 8]. The case presented here describes a complication that has not yet been reported, related to the migration of the device to the aortic arch.

First-in-Man Implantation of a New Hybrid Carotid Stent to Prevent Periprocedural Neurological Events During Carotid Artery Stenting

Purpose: To report the initial clinical experience with a new hybrid stent to prevent neurological events during carotid artery stenting. Case Report: A 77-year-old asymptomatic man presented with de novo high-grade stenosis (80%) of the right internal carotid artery (ICA) and occlusion of the contralateral ICA. He was referred for right ICA stenting with a 6/8-mmX40-mm Gore Carotid Stent under cerebral protection using the Gore Carotid Filter. The stent delivery system tracked well over the filter wire and deployment was precise. The result was satisfactory, with 10% residual stenosis. No neurological events occurred during 6 months of follow-up. Conclusion: Initial clinical experience with this new carotid hybrid stent showed satisfactory results, including ease of use, precise deployment, conformability to the wall, and protection against embolization.

Comparative results of doppler sonography after TIPS using covered and bare stents

OBJECTIVE Our purpose was to evaluate the role of sonography in the early follow-up of patients with a covered transjugular intrahepatic portosystemic shunt (TIPS). CONCLUSION Routine baseline Doppler sonography should occur 7-14 days after shunt placement unless malfunction or procedural complications are suspected.