Impact of stent design on the outcome of intervention for carotid bifurcation stenosis.

Over the past several years, there has been continued significant interest in refinement of patient selection, devices, procedures and protocols in an effort to optimize the outcome of percutaneous intervention for carotid bifurcation stenosis, including: ongoing National Institutes of Health and manufacturer trials and registries; the further refinement of existing devices and emergence of new platforms to attain distal embolic protection; ongoing study of what really constitutes a high-risk carotid surgery or stenting patient; and attention to device characteristics and patient-device matching. Within the latter area, considerable interest has focused on stent characteristics that have the potential to impact short and long-term outcome when compared with other stent design strategies when studied in large series. The stent in carotid artery intervention occupies a unique role in that after the embolic protection system has been removed, it is the main line of defense (in concert with aggressive dual antiplatelet therapy) from embolic and thromboembolic complications that may arise from the newly remodeled plaque after post-stent angioplasty. In this review, we aim to update the current status of efforts to relate stent design strategy to outcome in intervention for extracranial carotid artery disease with a focus primarily on the function of "free cell area" (typically lower with closed-cell stents and higher with open-cell stents) in analyses of outcome in carotid artery stenting. Also, the potential role of closed-cell vs. open-cell stent selection in other reports related to carotid artery stenting outcome or complications is reviewed. Rigorous studies have examined the issue of free cell area and arrived at disparate conclusions. Randomized data on the impact of free cell area and cell design strategy on carotid intervention are presently lacking. However, we believe sufficient data and rationale exist 1) to warrant ongoing study of the impact of stent design on outcome in carotid intervention; and 2) to make consideration of closed-cell (low free cell area) stent use a reasonable approach to device selection--when patient factors, lesion characteristics, or device availability make doing so possible.

Interim report of the SENTIS trial: cerebral perfusion augmentation via partial aortic occlusion in acute ischemic stroke.

AIM: The aim of this paper was to present the interim results of the the Safety and Efficacy of NeuroFlo Technology in Ischemic Stroke (SENTIS) trial. METHODS: The SENTIS study is a phase III, multi-center randomized prospective study to evaluate cerebral perfusion augmentation with partial aortic occlusion in acute ischemic stroke. The trial was designed to compare conventional management of stroke patients with stroke patients treated by partial occlusion of the abdominal aorta by the NeuroFlo device. Follow up was at 24 hours and 90 days. RESULTS: Of the 100 patients enrolled, 53 were randomized to treatment and 47 to control. Six patients enrolled to treatment were found to have specific exclusion criteria and were excluded. Therefore, 97 validated patients, 47 treated patients and 47 control patients were included in the analysis. Adverse events were evenly distributed, among the two cohorts of patients with 16 patients or 34% in each group, including fatal and non-fatal adverse events. However, the mortality was significantly lower for the treated population (6.4%) versus the control population (14.9%), with more stroke progression (8.5%) and hemorrhagic transformation of the stroke area (4.3%) in the control population. CONCLUSION: The SENTIS trial was designed to test the hypothesis that the NeuroFlo system is safe to be used in humans and able to produce cerebral perfusion augmentation, based on imaging and neurological assessment at 24 hours and at 90 days. The preliminary data yielded by the interim analysis showed that the population enrolled in the trial was rather homogeneous regarding age, baseline NIHSS scores, and other risk factors, suggesting that the treated and control cohorts were similar. The analysis also showed that the adverse events were rather comparable between the two groups, suggesting the treatment procedure to be safe enough for continuation of the trial. The NeuroFlo system so far proved to be safe enough for clinical use and seems to be promising in improving survival in the acute stroke population.

Use of percutaneous closure devices in the removal of central venous catheters from inadvertent arterial catheterizations.

Although rare, misplacement of central venous catheters in supra-aortic arteries is potentially fatal. Five patients had safe catheters removal using percutaneous closure devices. Three patients were coagulopathic, 3 under intensive care and 1 in immediate postoperative limb amputation. Patients were treated successfully, with immediate hemostasis and without complications in a mean follow-up of 12.5 months. Although the number of patients is small, the closure devices proved to be safe. This is a minimally invasive alternative technique in the management of large bore catheters removed from non-compressible puncture sites such as subclavian and brachiocephalic arteries.

Percutaneous interventions for pulmonary embolism.

Venous thromboembolism and pulmonary embolism (PE) is the third most common cardiovascular disease and a leading cause of death in the US. There are many risk factors related to PE. Traditional treatments are anticoagulation, systemic thrombolysis, and surgical thrombectomy. More recently, several minimally invasive procedures were introduced, which includes catheter-directed thrombolysis, percutaneous embolectomy, embolus fragmentation techniques, pulmonary artery stent placement or association of two or more of those techniques. In the present study the Authors review the role of the different techniques for the treatment of PE, and provide some guidelines and indications for treatment. The most popular devices and techniques are described in detail, and the efficacy of the techniques is discussed.

Stent-graft treatment of trauma to the supra-aortic arteries. A review.

Trauma to the carotid, subclavian, vertebral, or innominate arteries may be blunt or penetrating. Some injuries, such as those caused by central venous catheterization, are iatrogenic. Trauma-induced fistulas and pseudoaneurysms of the supra-aortic arteries are relatively rare, but may result in disabling neurologic symptoms or death. Traditional surgical approaches to supra-aortic artery trauma have high morbidity and mortality rates, especially in patients with multiple injuries and patients with a serious concomitant illness. The minimally invasive endovascular approach may offer an alternative that avoids the tissue damage, bleeding, infectious complications, pain and disability, long recovery time, and high financial cost associated with surgery. In the past 15 years, stent-grafts have evolved from bare-metal stents to which the operator attached autologous vein or a prosthetic material to manufactured balloon-expandable or self-expanding endoprosthetic systems. No devices designed specifically for use in the supra-aortic arteries are yet available. Nevertheless, the reported experience with stent-graft treatment of supra-aortic artery trauma is growing rapidly, although it remains limited to case reports and small series with relatively short follow-up times. Results have been very promising: complete lesion exclusion from the circulation and resolution of symptoms has been achieved in almost all cases, and few procedural complications and stent-graft stenoses and thromboses have been reported. The stent-graft approach warrants additional research on its long-term outcomes, as well as continued development of enhancements for the devices used.

How to optimize carotid artery stenting.

Carotid angioplasty and stenting is now an alternative to surgical endarterectomy to treat carotid occlusive disease and is becoming mainstream in medical practice. However, the information available, the procedure techniques and the technologies are still evolving and several issues are still being discussed. Mandatory training, familiarity with the indications and contraindications, knowledge of the technology and devices are paramount for the success, however, the devices for carotid stenting are still under development. The impact of stent design seems to be greater than previously appreciated. Carotid plaque morphology may be important for the indication of the procedure. The pre, trans, and postprocedure patient management of the patient is essential for reducing morbidity and mortality. Due to the devastating potential complications, compared with other endovascular and minimally invasive procedures, carotid stenting requires a much more strict scrutiny of the operators training and outcomes, since the improvement in the learning curve is accompanied by a comparative reduction in the complication rates. This article presents a review of the information available on how to optimize carotid stenting.

Filling of the aneurysmal sac with DEAC-glucosamine in an animal model of abdominal aortic aneurysm following stent-graft repair.

AIM: The aim of this study was to present the preliminary results of a technique of abdominal aortic aneurysm (AAA) sac filling in an attempt to obliterate the sac in a swine AAA model, using deacetylated-poly-N-acetyl glucosamine (DEAC-poly-N-acetyl glucosamine). METHODS: Eleven Yucatan pigs, 6 months of age, 40 kg -60 kg, were used to create an AAA with a Dacron pouch implanted surgically and left to mature for 2 weeks. One animal was used to establish the AAA creation procedures. Eight animals were used for AAA sac filling; of the 8 subjects 2 were used for acute studies, and 6 for longer-term studies. Two additional animals were used as controls without polymer sac filling. Two weeks after the AAA creation, a 13 mmx5.5 cm straight tube AneuRx stent-graft was placed to exclude the aneurysm. The aneurysmal sac was filled with a polymer, DEAC-poly-N-acetyl glucosamine at 1.5%, 70% deacetylated, mixed with iohexol. There was filling of a lumbar artery by the polymer in 2 animals. Endpoints were at 1, 2, 4, 6, 12 and 24 weeks, in the chronic study animals and 6 and 12 weeks in the control subjects, procedures consisting of aortography followed by necropsy and pathologic examination. RESULTS: The AAA creation and aneurysm sac filling was successful in all animals. An organized thrombus layer of about 2 mm in thickness was observed in all subjects along the Dacron aneurysm wall. All aneurysms were angiographically patent at the time of treatment, but fresher thrombus within the sac was seen in 4 subjects before the polymer injection. The stent-graft placement excluded the AAA sac and the polymer injection filled all AAA sacs. The AAA sac had acquired a firm rubbery consistency at the time of necropsy. There was mild inflammatory reaction to the Dacron material in the surrounding tissues and within the sac, to a lesser extent. Two animals developed paralysis of the hind limbs following treatment, most likely related to spinal ischemia, and were used as acute subjects. There was no recanalization of the aneurysm sac, during the follow-up time, ranging from 1 to 24 weeks in the treatment or control subjects. There was a 25% shrinkage of the AAA sac at 6th, 40% at 12th week and 75% by the 24th week. The 2 control subjects showed shrinkage of less than 25% at 6 and 12 weeks. There was replacement of the polymer/thrombus complex by connective tissue, fat tissue with capillary neovascularization in the treated subjects. Fibrosis and calcifications were also detected within the sac, mostly around the stent-graft and in contact with the aortic wall starting at 4 weeks. Control subjects did not show replacement of the thrombus by connective tissue or neovascularization. CONCLUSION: The results of this preliminary study support the aneurysm sac filling as a potential tool to exclude the aneurismal sac, promoting shrinkage of the AAA. DEAC -poly-N-acetyl glucosamine promotes clotting within the AAA sac with progressive replacement by connective tissue and neovascularization and may have a potential to prevent endoleaks. The polymer is easy to use, and it seems to have adequate gradual long-term replacement properties, preventing aneurysm sac recanalization.

Is there evidence that cerebral protection is beneficial? Clinical data.

Advances in angioplasty techniques and the development of low-profile, flexible, tapered nitinol stents designed specifically for carotid applications have made carotid artery stenting a viable alternative to carotid endarterectomy for treatment of occlusive disease of the carotid arteries. During the stenting process, however, debris may be released and cause distal embolization that can lead to stroke or death. Thus, several embolic protection devices have been developed for use in carotid stenting, two of which are available in the United States. In the past 5 years, data from several large trials, series, and registries of carotid artery stenting-reflecting the experience in thousands of patients-have become available. These investigations include the CAVATAS study, the Global Carotid Artery Stent Registry, the SAPPHIRE study, the ARCHeR trials, the CABERNET registry, the BEACH registry, the SECuRITY registry, the German Registry, and the EVA-3S trial. The studies have provided considerable evidence that use of an embolic protection device decreases the incidence of cerebral embolic events during carotid stenting in both symptomatic and asymptomatic patients. They have also shown that increased experience with angioplasty in the carotid artery decreases complication rates associated with the procedure, even when a protection device is not employed. Although the benefits of routine use of cerebral protection have not been confirmed by level 1 evidence, a consensus supports such use.

Techniques for carotid artery stenting under cerebral protection.

Carotid angioplasty and stenting is an alternative to carotid endarterectomy in the treatment of carotid artery stenosis. During the stenting process, however, distal embolization usually occurs, and the particles released may cause neurologic problems or death. Thus, the safety of carotid stenting depends partly on use of a cerebral protection device during the procedure. Three principal types of protection mechanisms have been developed: distal balloon occlusion, distal filtration, and proximal occlusion with or without reversal of flow. Products using these mechanisms have been manufactured by a variety of companies, and many are used routinely outside the United States (US). One distal filter, the RX Accunet, has been approved by the US Food and Drug Administration for clinical use. Large clinical trials of most of the newest carotid stents and cerebral protection devices are under way, and some initial results have been reported. Several clinical series in which cerebral protection was employed have also been described. Each type of protection device has advantages and disadvantages, which are discussed in this review.

Treatment of a solitary pulmonary sarcoidosis mass by CT-guided direct intralesional injection of corticosteroid.

A case is reported of 38-year-old woman with chest pain attributed to a left lung sarcoidosis mass. The mass failed to diminish and symptoms failed to resolve with systemic corticosteroid therapy. CT-guided direct intralesional transthoracic injection of dexamethasone resulted in resolution of the patient's symptoms and a dramatic reduction in the size of the mass within 2 months.

Endovascular treatment of abdominal aortic aneurysms: a review.

Abdominal aortic aneurysm (AAA) is a relatively common disease among the elderly population and may be present in up to 5.9% of the population aged 80 years. Abdominal aortic aneurysm more than 5 cm in diameter are more prone to rupture, with a significant mortality rate. Conventional surgical treatment is quite effective in the lower surgical risk population; however, in the population with a higher risk level the mortality and morbidity significantly increase. The development of less invasive techniques to treat AAA derived from the necessity to reduce the morbidity and mortality. The development of the endovascular endoprostheses was a significant landmark in the management of those patients with AAA, particularly the ones with increased risk. Although the stent-graft technology is still in its infancy, a large amount of information is available and an attempt to summarize this experience is presented herein. An extensive review of the stent-graft technology is presented, including variations in design and classification of the several systems available. Technical aspects of the use of endovascular prostheses are presented, as well as the most recent outcome information available. The problems of endoleaks is discussed and the techniques for treatment and outcomes presented. Finally, a summary of specific information on most of the devices available is presented.

Interventional therapy for pulmonary embolism.

Venous thromboembolism is a common cause of death. Acute massive pulmonary embolism (PE) is life-threatening and may require vigorous more invasive treatment. Several risk factors are related to increased incidence of massive PE. Anticoagulation is the most traditional treatment for PE but may not suffice in cases of massive PE. Systemic thrombolytic therapy, catheter-directed thrombolysis, percutaneous embolectomy, and more recently, percutaneous thrombus fragmentation techniques with a multitude of devices are now available to treat the most severe cases of massive PE. Successful treatment of PE includes implementation of a treatment protocol and the use of associated techniques and devices.

Hydrodynamic thrombectomy system versus pulse-spray thrombolysis for thrombosed hemodialysis grafts: a multicenter prospective randomized comparison.

PURPOSE: To evaluate the safety and efficacy of a hydrodynamic thrombectomy system in a prospective, multicenter randomized comparison with pulse-spray thrombolysis in hemodialysis grafts. MATERIALS AND METHODS: Nine centers enrolled 120 adult patients with recently (

Takayasu's arteritis associated with intrarenal vessel involvement.

Takayasu's arteritis (TA) is an inflammatory process frequently associated with stenosis and obliteration of the aorta and its primary branches. Renal manifestations of the disease include renal artery stenosis, hypertension, and ischemic kidney disease. To our knowledge, vasculitis involving intrarenal arteries has not been reported in association with TA. We report a case with clinical and arteriographic features of TA associated with involvement of intrarenal vessels.

Intravascular sonography in the assessment of traumatic injury of the thoracic aorta.

OBJECTIVE: The objective of this study is to describe the use of intravascular sonography in the evaluation of suspected injury of the thoracic aorta as an adjunctive tool to digital subtraction arteriography (DSA). SUBJECTS AND METHODS: Images of the thoracic aorta were obtained using DSA and intravascular sonography in 20 consecutive patients who underwent arteriography after chest trauma. A 6-French, 12.5-MHz sonography catheter was used for the intravascular sonography study. Diagnoses based on the review of both studies were compared. RESULTS: Five of 20 patients had aortic or great vessel injuries confirmed by surgery. Intravascular sonographic findings were positive (one false-positive) in seven patients, whereas DSA findings were positive in six patients (one false-positive and one false-negative). Surgery showed the lesion that was false-positive using both techniques to be a ductus diverticulum. Intravascular sonographic findings included intimal flaps, intramural lesions (hematomas), pseudoaneurysms, and perivascular hematomas. CONCLUSION: In our initial limited experience, intravascular sonography of the thoracic aorta and great vessels effectively identified traumatic injuries. Intramural injury without pseudoaneurysm formation or obvious intraluminal flap was visualized by intravascular sonography in one patient but was not detected by DSA. On the other hand, a ductus diverticulum was erroneously interpreted as trauma using both techniques. Intravascular sonography is a relatively new procedure with an obvious learning curve in the interpretation of the findings. An atypical ductus diverticulum may still be mistakenly interpreted as a sign of traumatic injury of the aorta. Familiarity with intravascular sonography in the setting of aortic trauma is necessary for correct interpretation of the images. The sonographic findings offer views of the aorta that are complementary to those of aortography.

Abdominal aortic aneurysm treatment: preliminary results with the Talent stent-graft system.

PURPOSE: To evaluate the treatment of abdominal aortic aneurysm (AAA) with use of the endoluminal Talent stent-graft (TSG). PATIENTS AND METHODS: In 10 men, AAA treatment was attempted with use of the TSG. All patients presented significant surgical risk, with chronic obstructive pulmonary disease and coronary arteriopathy. The mean age was 65.5 years (range, 57-82 years). The mean proximal neck diameter was 25.8 mm (range, 21.6-34 mm). Five of the TSGs were straight tubes and five were bifurcated systems. The main body of the TSG is made of a polyester graft material mounted on a self-expandable nitinol frame. The bifurcated system uses polytetrafluoroethylene (PTFE) material for the legs and extensions mounted on a self-expandable nitinol frame. The bifurcated grafts used a 22 to 27-F introducer and the extensions, a 18-F introducer through a surgical cutdown technique. RESULTS: The TSG system was successfully implanted in nine patients and failed in one because of dislodgment after deployment, which required conversion to surgery. Four leaks occurred initially. One was sealed off with balloon dilation at the end of the procedure, one leak was treated with an additional extension, another leak disappeared spontaneously in 30 days, and the other leak required embolization 4 weeks after discharge. Seven patients were discharged on the third day after the procedure, and two patients were discharged at 1 and 2 weeks, respectively. Blood transfusion was necessary in three patients because of hematoma at the incision site in two patients, which required surgical revision for hemostasis, and because of transoperative bleeding in one patient. Follow-up time ranged from 2 to 15 months. The only death occurred 5 days postoperatively as a consequence of ischemic colitis and multisystem organ failure in the only patient who required surgery. CONCLUSION: Treatment of AAA with the TSG system is effective for aneurysm exclusion. This device seems to provide a good alternative to surgery in patients who are otherwise considered to be at high risk for complications after direct surgical repair, but it is not without risk of complications.

Mechanical thrombectomy in acute and subacute thrombosis with use of the Amplatz device: arterial and venous applications.

PURPOSE: To perform a feasibility study of the Amplatz Thrombectomy Device (ATD) in a variety of vascular territories with acute or subacute thrombosis. MATERIALS AND METHODS: Thirteen patients (mean age, 44.6 years) with multiple risk factors who had acute/subacute thrombosis of the inferior vena cava (IVC) and iliac veins (n = 3), superior vena cava (SVC) and/or subclavian veins (n = 3), lower extremity polytetrafluoroethylene (PTFE) graft (n = 2), iliac artery (n = 2), portal vein and transjugular intrahepatic portosystemic shunt (TIPS) (n = 2), and an IVC to pulmonary artery Fontan conduit (n = 1), were treated by means of mechanical thrombectomy with use of the ATD. Thrombolysis failed to recanalize the vessels when used before thrombectomy for 12-34 hours in three patients, and was contraindicated in three other patients. Thrombolysis was used as a complement to the ATD procedure in five patients. RESULTS: Technical success was achieved in 11 patients, and procedure success was achieved in 10 patients. Failure was observed in the remaining three patients. One patient with a PTFE graft was successfully declotted but thrombosis occurred 2 weeks later, requiring surgery. The other patient with a PTFE graft did not improve and needed surgery to declot and treat the distal anastomosis and distal circulation. The two patients with an occluded iliac artery underwent successful declotting but rethrombosis occurred in one shortly after the procedure requiring thrombolytic therapy. One patient with TIPS thrombosis improved and another patient with a thrombosed portal vein did not improve after thrombectomy. CONCLUSION: The ATD is useful for recanalization of acute/subacute clotted native vessels and grafts. The application of the device is broad, and although declotting can be achieved in most cases, long-term success may be limited by anatomical and technical problems of the grafts and multifactorial clinical problems of severely sick patients, as was the case in the series. The use of additional thrombolytic therapy may be necessary in a number of patients.