The role of periradicular infiltration in dorsal root ganglion stimulation for chronic neuropathic pain.

BACKGROUND: Targeting the correct spinal level is essential in dorsal root ganglion (DRG) stimulation. Anatomical selection of the DRG alone is not ideal since the pain area is not necessarily confined to the borders of the dermatomes. This study aims to establish the role of periradicular infiltration therapy (PRT) in the preoperative assessment of the correct level for DRG stimulation performed under general anesthesia. METHOD: We report a prospective study of 20 patients selected for DRG stimulation and submitted to a PRT for identification of the spinal level. Lead implantation for the stimulation trial occurred under general anesthesia: 19 patients experienced positive results and underwent implantation of the pulse generator. All patients suffered from chronic neuropathic pain unresponsive to best medical treatment. PRT levels were compared with the levels targeted with DRG leads. Patients were followed for up to 12 months; pain intensity and coverage of the painful area were assessed. RESULTS: In 12 patients, the trial leads were placed on the same level as previously tested positive by PRT. In 6 patients, leads were placed in the PRT target and additionally in adjacent spinal levels. In one case, the selected target for the trial diverged from the PRT target because of intense fibrosis in the chosen level. Coverage of the target area of at least 50% was achieved by two-thirds of the patients. For the six subjects with additional implanted leads as a consequence of the PRT results, 80% achieved a coverage of at least 50%. A total of 47.4% of the patients achieved sustained significant pain relief in the last follow-up. None of the patients needed a repeated surgery for implantation of additional leads. CONCLUSIONS: PRT is a helpful tool to confirm the stimulation targets. A PRT preceding the stimulation trial is an additional opportunity to optimize the coverage of the target area with stimulation-induced paresthesia for patients operated under general anesthesia.

PFO closure: rational, procedure and devices.

Patent foramen ovale (PFO) is a common anatomical variant occurring in 20-25% of the population. In most cases, a PFO remains asymptomatic. However it allows for any venous particle such as thrombus, air or vasoactive substances to bypass the lung and enter the arterial circulation. Accordingly, PFO's have been linked to cryptogenic stroke, migraine and decompression illness. While the number of device closures have been increasing the therapy remains controversial as ­ until recently ­ data supporting PFO closure came from non randomized studies only. In this review we will discuss the existing data on PFO closure including results of the three randomized controlled trials comparing device closure with medical therapy in patients with cryptogenic stroke. We will also focus on the implantation technique, the complications and the different devices that are used for this procedure.

FiberNet--a new embolic protection device for carotid artery stenting.

BACKGROUND: Though distal filter protection during carotid stenting reduces the risk of cerebrovascular events, periprocedural stroke remains a risk despite their broad usage. This observation may be related to the pore size of common filters. The FiberNet distal filter system is unique by its very small pore size (40 µm) as well as its low profile and flexibility. Little data is available regarding the clinical performance and safety of this device. PURPOSE: The aim was the evaluation of the safety of the FiberNet embolic protection system during carotid artery stenting. METHODS: All consecutive patients treated with carotid stenting at our institution using the FiberNet device were systematically followed. Primary endpoint was the rate of all death and stroke within 30 days of the procedure. RESULTS: Carotid artery stenting using the FiberNet embolic protection system was performed in 54 patients. The procedure was technical successful in all patients. Three patients (5.5%) had a TIA. Amauosis fugax occurred in two patients (3.7%). One patient (1.9%) had a minor stroke with hemiparesis of the left arm and face which resolved completely within 48 hr after the procedure. No patient died or suffered a major stroke. CONCLUSION: The safety and feasibility of the FiberNet distal protection system appears to be at least equivalent to that reported in studies using conventional distal filter protection.

A novel technique to remove a right atrial thrombotic mass attached to a patent foramen ovale (PFO) closure device.

Any percutaneously implanted foreign device carries the potential risk of thrombus formation. If a thrombus is detected after device implantation during follow-up, in most cases anticoagulation therapy is sufficient to resolve the thrombus. If the anticoagulation concept fails, surgery has been the only alternative option to remove thrombotic masses. This case of a patient with a large thrombus formation attached to a PFO closure device who denied surgery demonstrates that mechanical percutaneous clot retrieval is feasible with the AngioVac aspiration system (Vortex Medical, Inc., Norwell, MA). © 2013 Wiley Periodicals, Inc.

Complications during carotid artery stenting.

Carotid stenting has become a commonly used procedure for the treatment of carotid artery stenosis. Though equipment and techniques have improved tremendously over the recent 3 decades, complications do occur. It is important for carotid operators to be familiar with potential complications and adverse events. In this article complications and adverse events of carotid stenting including those that are related to the vascular access site, vessel spasm, dissection, perforation, thrombotic occlusion and hemodynamic instability and arrhythmias are reviewed. In addition, management strategies are discussed.

Acute and long-term results of carotid stenting under proximal embolic protection using the Gore Flow Reversal System.

OBJECTIVE: This study evaluates short- and long-term results of CAS with the Gore Flow Reversal System (GFRS). BACKGROUND: Embolic protection devices are of fundamental importance in carotid artery stenting (CAS). Proximal protection has potential advantages compared with distal protection. Limited data are available regarding the safety of the proximal GFRS. METHODS: CAS was performed with the GFRS. Patients' neurological status was assessed during the intervention and at follow-up. Results of patients treated before 2006 were also compared to those of patients treated after 2006 because of changes in device design. RESULTS: CAS was performed in 86 patients with 87 stenoses (symptomatic in 37%). The procedure was technically successful in all cases. In 11 patients a transient periprocedural neurologic deficit occurred related to temporary cerebral flow compromise during balloon occlusion with complete resolution at completion of the procedure. The stroke/death rate at one month was 2.3% with a combined ipsilateral stroke and death rate at one year of 4.6%. There was no significant difference in event rates between the newer and older device version. Overall follow-up time was 484 ± 3.4 patient years with a range of 0 to 119 months. The average yearly ipsilateral stroke rate including the first 30 days was 0.96%. CONCLUSION: Our results demonstrate that CAS using the GFRS is safe whether the original or new device versions were used. The periprocedural stroke rate is at least as low as the stroke rate reported using distal protection. The long-term stroke rate after CAS is low.

Percutaneous approaches to mitral valve regurgitation.

Mitral regurgitation is a common problem associated with significant morbidity and mortality. Mitral valve surgery has been the treatment of choice for symptomatic patients with severe mitral regurgitation or asymptomatic patients with high-risk clinical features. However, a significant number of patients remain untreated related mainly due to a projected high surgical risk. Therefore, alternative percutaneous treatments including indirect annuloplasty, which takes advantage of the coronary sinus, and direct annuloplasty have recently been explored. Most recently, promising results of the first randomized trial comparing conventional mitral valve surgery to percutaneous therapy with a clip creating a double orifice much like the surgical Alfieri approach have been presented. Finally, percutaneous mitral valve replacement in an animal model has been pursued. This review serves to familiarize the reader with some anatomical concepts and devices for percutaneous mitral repair.

Comparison of stent free cell area and cerebral lesions after unprotected carotid artery stent placement.

OBJECTIVE: This study evaluates the correlation between closed, semi-closed and open-cell stent design and the association between stent type and clinical outcome as well as magnetic resonance imaging (MRI) findings. DESIGN: A total of 194 patients who underwent unprotected carotid artery stenting (CAS) as well as diffusion-weighted magnetic resonance imaging (DW-MRI) before and after intervention were retrospectively reviewed. MATERIALS AND METHODS: Three stent designs were studied: closed cell, semi-closed cell and open cell. Spearman's Rho test was performed between the stent free cell area and the number and area of ischaemic lesions found after intervention. Adverse events were evaluated. RESULTS: There was no significant difference in clinical outcome between the three stent groups (Zilver, Cook Europe, Denmark; Smart, Codman, MA; and Wallstent, Stryker, MN, USA). A significant correlation was found between the stent free cell area and the number and area of new ischaemic lesions on DW-MRI (P = 0.023). There were significantly fewer new lesions with an open-cell design (Zilver; 12.76 mm(2) free cell area) than with a closed-cell design (Wallstent; 1.08 mm(2) free cell area). CONCLUSIONS: Open-cell stent was related to a lower number and area of silent cerebral ischaemic lesions after unprotected CAS. However, clinical outcome, measured by incidence of adverse events and clinical neurologic assessment, was not significantly different between patients with different stent designs.

Endovascular stroke treatment today.

The purpose of this study was to review current treatment options in acute ischemic stroke, focusing on the latest advances in the field of mechanical recanalization. These devices recently made available for endovascular intracranial thrombectomy show great potential in acute stroke treatments. Compelling evidence of their recanalization efficacy comes from current mechanical embolectomy trials. In addition to allowing an extension of the therapeutic time window, mechanical recanalization devices can be used without adjuvant thrombolytic therapy, thus diminishing the intracranial bleeding risk. Therefore, these devices are particularly suitable in patients in whom thrombolytic therapy is contraindicated. IV and IA thrombolysis and bridging therapy are viable options in acute stroke treatment. Mechanical recanalization devices can potentially have a clinically relevant impact in the interventional treatment of stroke, but at the present time, a randomized study would be beneficial.

Catheter-based renal sympathectomy.

The sympathetic nervous system via its effect on the kidney maintains a key role in blood pressure regulation and in the pathogenesis of hypertension. In turn, the kidney receives a dense innervation of afferent sympathetic fibers allowing it to effectively modulate the sympathetic tone. Hence, the kidney can be both culprit and victim of increased sympathetic activity. In addition, conditions such as congestive heart failure, chronic renal failure or the metabolic syndrome are associated with an increased sympathetic activity whether or not hypertension is present. On this account, both the sympathetic nervous system and the kidney were identified as potential therapeutic targets in the treatment of hypertension and other conditions associated with a high sympathetic tone. Initial investigations focused on surgical removal of the sympathetic trunk, unfortunately accompanied by operative mortality and major side effects. More specific methods of disrupting interactions between the sympathetic nervous system and the kidneys were subsequently explored including the removal of diseased kidneys and, more recently, minimally invasive severance of the renal sympathetic nerves. Currently, most hypertensive patients can be treated by effective antihypertensive drugs. Notwithstanding, a small group of hypertensive patients remains suboptimally controlled despite identification of potential causes and appropriate treatment. In this group an elevated sympathetic tone may be a significant contributor to treatment resistance and selective renal sympathectomy may be beneficial. The role of the sympathetic nervous system in blood pressure control and the effect of selective sympathectomy are discussed in this review.

Transcatheter closure of patent foramen ovale, atrial septal defect and left atrial appendage.

Intracardiac defects such as atrial septal defect (ASD) and patent foramen ovale (PFO) are common forms of congenital intracardiac apertures which can be successfully closed percutaneously. Since the initial description of an atrial septal defect closure device in the mid 1970s by King and Mills, transcatheter closure of atrial septal defects and patent foramen ovale using various devices has now become an established practice in many centers. The left atrial appendage is a trabeculated remnant of the embryonic left atrium. This is an important source of emboli related to atrial fibrillation. Closure of the left atrial appendage is designed to reduce the risk of stroke in patients with atrial fibrillation. This article reviews the current indications and latest developments in catheter closure of PFO, ASD and left atrial appendage.

Chronic monitoring of pulmonary artery pressure in patients with severe heart failure: multicentre experience of the monitoring Pulmonary Artery Pressure by Implantable device Responding to Ultrasonic Signal (PAPIRUS) II study.

OBJECTIVE: To evaluate the feasibility and safety of home monitoring of chronic heart failure (CHF) patients using acoustic wireless communication with an implant directly measuring pulmonary artery (PA) pressures. DESIGN: The PAPIRUS (Pulmonary Artery Pressure by Implantable device Responding to Ultrasonic Signal) II trial was a prospective, multicentre phase I study. PATIENTS: 31 patients with CHF in New York Heart Association class III-IV. INTERVENTIONS: Implantation of a miniature device in the right pulmonary artery (PA) responding to ultrasonic signal that enables wireless recording of a complete PA pressure curve. MAIN OUTCOME MEASURES: The primary end points were rates of serious adverse device- or implantation-related events at 6 months. Secondary end points included accuracy of the measured PA pressure, functionality of the system and evaluation of pressure readings at different postures. RESULTS: The two safety end points were met with no serious adverse events related to the device or implantation. Pressure tracings at 6 months were almost identical to those obtained simultaneously by Millar catheter. Variations of PA diastolic pressure were observed in relation to posture (standing 6.4 (SD 3.4) mm Hg lower than supine, p<0.001). A total of 4627 home measurements were successfully performed by 23 patients using a simple-to-operate hand-held home-unit for daily measurements. The median compliance with daily monitoring was 86%. CONCLUSIONS: Meeting the prespecified safety objective of this study warrants a randomised trial to fully evaluate the potential of home monitoring by this miniature PA implant in guiding long-term management in CHF.

[Implementation of cross-compliance in the area of animal welfare]. / Umsetzung von Cross Compliance im Bereich Tierschutz.

From 1 January 2007, requirements concerning animal welfare were introduced with effect to cross-compliance. Farmers receiving single payment as well as agri-environmental payments (payments of second pillar) shall respect the statutory management requirements of the following 3 directives in the area of animal welfare: Council Directive 91/629/EEC laying down minimum standards for the protection of calves; Council Directive 91/630/EEC laying down minimum standards for the protection of pigs; Council Directive 98/58/EC concerning the protection of animals kept for farming purposes. The competent authority shall carry out annual systematic inspections on at least 1% of all farmers submitting payments on the basis of a risk analysis and partly at random. In case of non-compliance with the conditions due to specific rules, there will be a reduction or cancellation of the payments to be granted in the calendar year in which non-compliance occurs. Cross-compliance controls should take place on the basis of documented procedures so as to ensure that these controls are carried out uniformly and are of a consistently high quality. For this purpose, a working group composed of representatives from the Federal Ministry of Food, Agriculture and Consumer Protection and from the Lander developed uniform control reports in order to monitor compliance and a guidance booklet for control execution of animal welfare requirements. In the control report (Level 1), the outcomes of inspections of all systematic testable animal welfare requirements are summarized in 6 items. Furthermore, the non-systematically testable requirements are integrated in the control report as a independent item. The guidance booklet (Level 2) with a matrix of validation serves as a specification for on-the-spot checks. Where appropriate, on-the-spot checks provided for cross-compliance and any other checks in animal welfare rules as well as requirements to animal identification and registration shall be carried out at the same time in Baden-Württemberg (integrated control system). Farmers subjected to on-the-spot checks shall be selected on the basis of a centralized common risk analysis and partly at random. This is the best way of safeguarding that the control rate will not be much higher than the established 1% with a minimum administrative burden and costs for farmers and competent control authorities. Integrated check lists for on-the-spot checks were established which take into account systematic cross compliance inspections to improve compliance with 3 existing standards in the area of animal welfare and official controls as proved in Council Directives concerning animal welfare and Regulation (EC) No 882/2004. All staff of the competent authorities performing controls received, for their area of competence, appropriate training enabling them to make their duties competently and to carry out controls in a consistent manner. Integrated systematic controls are very time-consuming and a burden for farmers and the competent authorities. For the beginning of this year, we will expect a discharge by Decision (EC) 2006/778. A controlling system was installed to ensure that cross compliance rules are applied consistently, for example by making subsequent controls by controlling institutions.

The safety and efficacy of an extravascular, water-soluble sealant for vascular closure: initial clinical results for Mynx.

OBJECTIVE: The purpose of this study was to evaluate the hemostatic efficacy and safety of the Mynx extravascular sealant for femoral artery closure. BACKGROUND: The Mynx device is an extra-arterial vascular closure technology utilizing a water-soluble, porous, polyethylene glycol matrix that immediately seals the arteriotomy by rapidly absorbing subcutaneous fluids and expanding in the tissue tract and then, resorbs within 30 days. METHODS: The Mynx study was a prospective, multicenter, single-arm clinical investigation conducted at five European centers. The safety and effectiveness of the Mynx device was evaluated in patients following diagnostic or interventional endovascular procedures performed through 5 Fr, 6 Fr, or 7 Fr introducer sheaths in the common femoral artery. The primary safety endpoint was the combined rate of major complications within 30 days (+/-7 days). The primary efficacy endpoints were time to hemostasis and time to ambulation. RESULTS: Patient enrollment included 190 patients with 50% having undergone diagnostic catheterization and 50% interventional procedures with a mean activated clotting time of 221 sec. One (0.5%) major vascular complication (transfusion) occurred in one patient. No device-precipitated complications associated with serious clinical sequelae were reported. Mean (+/- standard deviation) times to hemostasis and ambulation were 1.3 +/- 2.3 min and 2.6 +/- 2.6 hr, respectively. There was no significant difference in median times to hemostasis between diagnostic and interventional patients (0.5 vs. 0.6 min). CONCLUSIONS: The initial experience with the extra-arterial Mynx closure technology supports hemostatic safety and efficacy in patients undergoing diagnostic and interventional catheterization procedures.

Carotid artery stenting: where are we now?

Carotid artery disease is a frequent risk factor for ischemic stroke. Carotid endarterectomy was considered to be the standard treatment for high graded stenosis until carotid artery stenting (CAS) developed with promising results in early series and randomized trials. At present, stenting is supported in patients at high risk for surgery. Randomized trials analyzing low risk patient groups and studying the long-term results of CAS are necessary and partly underway. Although randomized trials are not yet available, current evidence suggests that cerebral protection devices reduce the number of neurological events. This review discusses the results of randomized trials and clinical series.