Feasibility, safety, and preliminary efficacy of a novel ePTFE-covered self-expanding stent in saphenous vein graft lesions: The Symbiot II trial

ePTFE-based biomedical devices: An overview of surgical efficiency

Polytetrafluoroethylene (PTFE) is a ubiquitous material used for implants and medical devices in general because of its high biocompatibility and inertness: blood vessel, heart, table jawbone, nose, eyes, or abdominal wall can benefit from its properties in case of disease or injury. Its expanded version, ePTFE is an improved version of PTFE with better mechanical properties, which extends its medical applications. A material as frequently used as ePTFE with these exceptional properties deserves a review of its main uses, developments, and possibility of improvements. In this systematic review, we examined clinical trials related to ePTFE-based medical devices from the literature. Then, we excluded all trials using ePTFE as a control to test other devices. ePTFE-coated stents, hemodialysis and bypass grafts, guided bone and tissue regeneration membranes, hernia and heart repair and other devices are reviewed. The rates of success using these devices and their efficiency compared to other materials used for the same purposes are reported. ePTFE appears to be more or just as efficient compared to them. Some success rates remain low, suggesting the need of improvement ePTFE for medical applications.

Endoscopic endonasal skull base surgery: analysis of complications in the authors' initial 800 patients

Object

The development of endoscopic endonasal approaches, albeit in the early stages, represents part of the continuous evolution of skull base surgery. During this early period, it is important to determine the safety of these approaches by analyzing surgical complications to identify and eliminate their causes.

Methods

The authors reviewed all perioperative complications associated with endoscopic endonasal skull base surgeries performed between July 1998 and June 2007 at the University of Pittsburgh Medical Center.

Results

This study includes the data for the authors' first 800 patients, comprising 399 male (49.9%) and 401 female (50.1%) patients with a mean age of 49.21 years (range 3–96 years). Pituitary adenomas (39.1%) and meningiomas (11.8%) were the 2 most common pathologies. A postoperative CSF leak represented the most common complication, occurring in 15.9% of the patients. All patients with a postoperative CSF leak were successfully treated with a lumbar drain and/or another endoscopic approach, except for 1 patient who required a transcranial repair. The incidence of postoperative CSF leaks decreased significantly with the adoption of vascularized tissue for reconstruction of the skull base (< 6%). Transient neurological deficits occurred in 20 patients (2.5%) and permanent neurological deficits in 14 patients (1.8%). Intracranial infection and systemic complications were encountered and successfully treated in 13 (1.6%) and 17 (2.1%) patients, respectively. Seven patients died during the 30-day perioperative period, 6 of systemic illness and 1 of infection (overall mortality 0.9%).

Conclusions

Endoscopic endonasal skull base surgery provides a viable median corridor based on anatomical landmarks and is customized according to the specific pathological process. This corridor should be considered as the sole access or may be combined with traditional approaches. With the incremental acquisition of skills and experience, endoscopic endonasal approaches have an acceptable safety profile in select patients presenting with various skull base pathologies.

Massive coronary perforation and shock: From appropriate labeling to appropriate calls

Coronary perforation is a rare, unpredictable and dreaded complication of percutaneous coronary Intervention. With Ellis Grade 3 perforations the only effective treatment includes temporary balloon occlusion of the perforated coronary artery and placement of JOSTENT GraftMaster stent to cover the perforation. The authors describe coronary perforation during proximal right coronary artery (RCA) stenting, resulting in immediate cardiogenic shock. The patient was treated with temporary balloon occlusion of the RCA, reversal of anti-coagulation, sealing of the perforation with a GraftMaster stent, inotropes, intra-aortic balloon counterpulsation (IABC) and surgical drainage the pericardial space. The authors describe the rational of their therapeutic strategy. The methodology and pitfalls of GraftMaster deployment, in patients with massive coronary perforation are discussed. This report also emphasizes, that as opposed to manufactures instructions and all previous manuscripts, GraftMaster can be easily deployed via conventional 6F guiding catheters with internal diameter 0.070 inch (1.8 mm).

Application of covered stent grafts for intracranial vertebral artery dissecting aneurysms

Object

Utilization of covered stent grafts in treating neurovascular disorders has been reported, but their efficacy and safety in vertebral artery (VA) dissecting aneurysms needs further investigation.

Methods

Six cases are presented involving VA dissecting aneurysms that were treated by positioning a covered stent graft. Two aneurysms were located distal to the posterior inferior cerebellar artery, and 4 were located proximal to the posterior inferior cerebellar artery. Aspirin as well as ticlopidine or clopidogrel were administered after the procedure to prevent stent-related thrombosis. All patients were followed up both angiographically and clinically.

Results

Five of the 6 patients underwent successful placement of a covered stent graft. The covered stent could not reach the level of the aneurysm in 1 patient with serious vasospasm who died secondary to severe subarachnoid hemorrhage that occurred 3 days later. Patient follow-up ranged from 6 to 14 months (mean 10.4 months), and demonstrated complete stabilization of the obliterated aneurysms, and no obvious intimal hyperplasia. No procedure-related complications such as stenosis or embolization occurred in the 5 patients with successful stent graft placement.

Conclusions

Although long-term follow-up studies using a greater number of patients is required for further validation of this technique, this preliminary assessment shows that covered stent graft placement is an efficient, safe, and microinvasive technique, and is a promising tool in treating intracranial VA dissecting aneurysms.

Successful trapping of an organized thrombus in a coronary artery aneurysm in myocardial infarction: case report and literature review

A 44-year-old female presented with acute inferior myocardial infarction. Emergency coronary angiography showed an aneurysm of the proximal right coronary artery and an occlusion of the vessel downstream due to a huge organized thrombus. Mechanical fragmentation, glycoprotein IIb/IIIa antagonist, and intracoronary thrombolysis were all tested without success. Finally, the aneurysm was covered with a standard bare metal stent in order to trap the thrombus between the stent and the vessel wall and at least partially in the aneurysm. The strategy was successful, and after 1 week, the blood flow in the right coronary artery was normal; however, the aneurysm remained. After 6 months, there was significant in-stent restenosis of the proximal and mid segments of the right coronary artery but no evidence of the aneurysm. The restenosis was treated with two drug-eluting stents, leading to an excellent result after a further 6 months. The patient was free of symptoms and the left ventricular ejection fraction was within the normal range.

Pseudoaneurysms of Hepatic Artery Branches: Treatment with Self-expanding Stent-grafts in Two Cases

Pseudoaneurysms of the hepatic artery or its branches are rare complications with several potential causes. Herein, the authors report two cases of pseudoaneurysms of hepatic artery branches, one secondary to laparoscopic surgery and the other probably due to malignancy. The pseudoaneurysms were treated with the placement of self-expanding stent-grafts. Complete and prompt occlusion of the pseudoaneurysm was achieved in both patients, with resolution of symptoms and preservation of the blood flow in the parent arterial branch at long-term follow-up.

Pivotal, randomized U.S. study of the Symbiot™ covered stent system in patients with saphenous vein graft disease: Eight-month angiographic and clinical results from the Symbiot III trial

OBJECTIVES

The purpose of this study was to evaluate the clinical and angiographic outcomes of the Symbiot ePTFE covered stent versus bare metal stents (BMS) for the treatment of saphenous vein graft (SVG) disease.

BACKGROUND

The Symbiot stent was developed to reduce periprocedural complications, by potentially preventing distal embolization, and to serve as a possible barrier to cell migration, thus reducing restenosis.

METHODS

Symbiot III is a prospective, randomized trial of 400 patients at 45 US sites, with 201 patients in the Symbiot group and 199 in the BMS group. Randomization was stratified based on the intended use of embolic protection devices and glycoprotein IIb/IIIa inhibitors. The primary endpoint was percent diameter stenosis (%DS) as measured by quantitative coronary angiography at 8 months. Secondary endpoints included MACE (cardiac death, MI, TVR).

RESULTS

The groups were well matched for all baseline clinical and lesion characteristics. At 8 months, %DS was comparable between groups (30.9% Symbiot, 31.9% BMS, P = 0.80). Although the rates of binary restenosis in the stented segment were similar (29.1% Symbiot, 21.9% BMS, P = 0.17), more patients in the Symbiot group had binary restenosis at the proximal edge (9.0% Symbiot, 1.8% BMS, P = 0.0211). There was no difference in the incidence of MACE between groups (30.6% Symbiot, 26.6% BMS, P = 0.43).

CONCLUSIONS

This study failed to show an advantage for the Symbiot stent in the treatment of degenerated SVGs. This PTFE covered stent does not appear to act as a barrier to prevent restenosis.