Coronary stent grafts covered by a polytetrafluoroethylene membrane

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.

Initial experience with intracranial stent-graft use. Technical notes

SUMMARY

We describe our initial experience with the placement of two premounted balloon expandable intracranial Jostent stent-grafts within the intracavernous internal carotid artery for the treatment of a symptomatic large intracavernous aneurysm in one case and a post-traumatic caroticocavernous fistula in the second. Among the initial technical complications we encountered were stent-graft migration and rapidly progressive intragraft thrombosis, with delayed sealing of the stent-graft coverings and exclusion of the pathologies relating to the use of abciximab in both cases. Despite these initial problems both cases had excellent short-term clinical outcomes with angiographic exclusion of both lesions by day three and good clinical and angiographic outcomes at one and two months respectively.

Endovascular Treatment of a Giant Intracranial Aneurysm with a Stent-Graft

This report describes a giant intracavernous carotid aneurysm successfully treated by the placement of a single covered stent. A 40-year-old woman was admitted with a progressive diplopia in relation with palsy of the IV and VI cranial nerves. Magnetic resonance imaging revealed an intracavernous giant aneurysm located at the bifurcation between the origin of a trigeminal artery and the intracavernous portion of the right internal carotid artery. A covered stent was successfully placed, and complete exclusion of the aneurysm was confirmed at 11-month follow-up angiography. The use of covered stents in intracranial vascular structures can now be a feasible way of treating selected cases of wide-necked intracranial aneurysms.

Acute and long-term outcome after coronary artery perforation during percutaneous coronary interventions

BACKGROUND

Coronary artery perforation is a rare but serious complication of percutaneous coronary interventions (PCI).

METHODS

We reviewed our database for cases of overt coronary perforation during PCI procedures. Hospital charts, procedural reports, and coronary angiograms of these patients were reviewed, with particular emphasis on mechanisms of perforation, management of the complication, and clinical outcome.

RESULTS

Between 01/1998 and 12/2003, a total of 19 cases (mean age: 66+/-8 years, 13 male) of coronary perforation occurred during 6433 PCI procedures performed within this period (incidence: 0.3%). In 12/19 (63%) cases, perforation occurred during recanalisation procedures of chronic total occlusions of coronary arteries. In all but one patient, non-surgical management was attempted: 2 out of 19 (11%) patients were treated conservatively by reversal of heparin anticoagulation. Prolonged balloon inflation at the perforation site was applied in 10/19 (53%) patients. Six (32%) patients received stents (5 of them received covered stentgrafts), 3 (16%) patients developed cardiac tamponade requiring percardiocentesis, and only 2 (11%) patients underwent bailout surgical repair. There were 2 (11%) deaths early after the procedure.

CONCLUSION

Coronary perforation during PCI is a rare complication, but is associated with significant morbidity and mortality. In the majority of patients, non-surgical management is both feasible and associated with a high success-rate.

Treatment of Extracranial and Intracranial Aneurysms and Arteriovenous Fistulae Using Stent Grafts

OBJECTIVE:

Treatment of 11 patients with aneurysms or arteriovenous fistulae of the craniocervical arteries with stent grafts.

METHODS:

Peripheral stent grafts were deployed in two extracranial internal carotid arteries. Coronary stent grafts were used to treat two giant aneurysms, five direct carotid-cavernous fistulae, one vertebrojugular fistula, and two dissecting aneurysms of the vertebral artery (V2 and V4).

RESULTS:

Stent grafts were used successfully in two extracranial internal carotid and two extracranial vertebral arteries, one dissecting aneurysm of the intracranial vertebral artery, one giant aneurysm and one pseudoaneurysm of the cavernous internal carotid artery, and five direct carotid-cavernous sinus fistulae. Angiographic follow-up examinations (available in nine patients; obtained at 3 mo to 5 yr; average, 24 mo) revealed normal vessel caliber, and the stent grafts in all 9 of 11 initial patients were patent. There was a recurrent saccular aneurysm adjacent to the stent graft in the patient with the intracranial vertebral artery aneurysm. The following five complications were encountered: transient hemiparesis (n = 2), increased hemiparesis, post-procedural management-related fatality, and ICA dissection. In six patients, stent graft deployment was accomplished without any technical or clinical complication. There were no permanent neurological deficits consequent to stent graft placement.

CONCLUSION:

Stent grafts are a useful tool for the endovascular treatment of head and neck aneurysms and direct arteriovenous fistulae in selected patients. The major disadvantage of the currently available stent grafts is their lack of mechanical flexibility. Maneuvering stent grafts in the intracranial arteries carries the risk of iatrogenic vessel dissection and may require supportive measures and protection of the target site by conventional stents.

A randomized trial of polytetrafluoroethylene-membrane-covered stents compared with conventional stents in aortocoronary saphenous vein grafts

We compared a conventional stent (Jostent Flex, Jomed GmbH, Rangendingen, Germany) with a polytetrafluoroethylene (PTFE)-membrane-covered stent (Jostent Stentgraft) in patients undergoing intervention of a stenosis in an obstructed vein graft. The use of stents improved results of percutaneous revascularization of obstructed vein grafts, but did not demonstrate the reduced elevated restenosis rate. In addition, long-term clinical event rate is still high compared with intervention in native vessels. Observational studies suggested that stents covered with a PTFE membrane might be associated with a low complication and restenosis rate in venous bypass grafts. This prospective multicenter study included a total of 211 patients who were randomly assigned to receive either a Flex stent or Stentgraft. The primary end point was binary restenosis rate at six months by core lab quantitative coronary angiography. Acute success and procedural events were comparable between the two groups. Restenosis rate was not significantly different between the Flex (20%) and the Stentgraft (29%) groups (p = 0.15), although there was a nonsignificant trend toward a higher late occlusion rate in the Stentgraft group (7% vs. 16%, p = 0.069) at follow-up. Likewise, after a mean observation period of 14 months, cumulative event rates (death, myocardial infarction, or target lesion revascularization) were comparable in the two groups (31% vs. 31%, p = 0.93). This controlled trial does not indicate a superiority of the PTFE-membrane-covered Stentgraft compared with a conventional stent with respect to acute results, restenosis, or clinical event rates.

Randomized evaluation of polytetrafluoroethylene-covered stent in saphenous vein grafts: the Randomized Evaluation of polytetrafluoroethylene COVERed stent in Saphenous vein grafts (RECOVERS) Trial

BACKGROUND

Treatment of lesions located in saphenous vein grafts (SVGs) is associated with increased procedural risk and a high rate of restenosis.

METHODS AND RESULTS

We conducted a randomized, multicenter trial to evaluate the usefulness of a polytetrafluoroethylene (PTFE)-covered stent compared with a bare stainless steel (SS) stent for prevention of restenosis and major adverse cardiac events (MACE) in patients undergoing SVG treatment. The primary end point was angiographic restenosis at 6 months. Secondary end points were 30-day and 6-month MACE rates, defined as the cumulative of death, myocardial infarction (MI), and target lesion revascularization. Between September 1999 and January 2002, 301 patients with SVG lesions were randomized to either the PTFE-covered JoStent coronary stent graft (PTFE group, n=156) or the SS JoFlex stent (control group, n=145). Angiographic and procedural success rates were similar between the 2 groups (97.4% versus 97.9% and 87.3% versus 93.8%, respectively). The incidence of 30-day MACE was higher in the PTFE group (10.9% versus 4.1%, P=0.047) and was mainly attributed to MI (10.3% versus 3.4%, P=0.037). The primary end point, the restenosis rate at 6-month follow-up, was similar between the 2 groups (24.2% versus 24.8%, P=0.237). Although the 6-month non-Q-wave MI rate was higher in the PTFE group (12.8% versus 4.1%, P=0.013), the cumulative MACE rate was not different (23.1% versus 15.9%, P=0.153).

CONCLUSIONS

The study did not demonstrate a difference in restenosis rate and 6-month clinical outcome between the PTFE-covered stent and the SS stent for treatment of SVG lesions. However, a higher incidence of nonfatal myocardial infarctions was found in patients treated with the PTFE-covered stent.

Elective placement of covered stents in native coronary arteries

PURPOSE

To study the feasibility of placing a polytetrafluoroethylene (PTFE)-covered stent graft into native coronary arteries and assess the complications and the restenosis rate.

MATERIAL AND METHODS

Fifty consecutive patients with stable angina pectoris were included and the stent graft was placed into native coronary arteries. Clinical and angiographic follow-up were performed after 6 months.

RESULTS

The stent grafts were successfully placed in all patients. The mean reference diameter was 3.3 +/- 0.6 mm. During follow-up the stent grafts occluded in patients after 1, 2 and 2.5 months and one more was occluded at 6 months. Three patients experienced myocardial infarction, 2 Q wave and one non-Q wave. After 6 months 42 (84%) patients had angina NYHA class 0 or 1. Target vessel revascularization was done in 11 cases for restenosis in the graft (n = 4), outside the graft (n = 3) and both (n = 4), giving a restenosis rate of 24%. The total major adverse coronary events at 6 months was 24%.

CONCLUSION

The stent graft was deployed with a high success rate. The restenosis rate was not higher than expected for bare stents. However, this study showed that subacute occlusion may occur more frequently and we therefore recommend that ticlopidine or clopidogrel treatment should be prolonged to at least 3 months.

Successful management of osteal perforation of left anterior descending artery with coated stent

Coronary perforation is a rare complication of percutaneous coronary intervention. We report a case of left anterior descending artery osteal perforation that led to acute cardiac tamponade during excimer laser angioplasty. Perforation was successfully covered with a PTFE-coated stent with preserved distal coronary flow.

Biocompatibility and performance of the Wallstent and the Wallgraft, Jostent, and Hemobahn stent-grafts in a sheep model

PURPOSE

Three recently developed stent-grafts and the Wallstent were compared directly in an ovine animal model with regard to performance and biocompatibility.

MATERIALS AND METHODS

Three stent-grafts, the Hemobahn (polytetrafluoroethylene [ePTFE]/nitinol), Wallgraft (polyester/Ni-Co-Ti-steel alloy), and Jostent peripheral stent-graft (balloon-expandable ePTFE/stainless steel), and the Wallstent (Ni-Co-Ti-steel alloy), were implanted in sheep iliac arteries (one type of each stent or stent-graft per animal, n = 8). Pre- and postimplantation luminal diameters were measured for each prosthesis and implantation site. Angiography, intravascular ultrasonography (IVUS), and histomorphometric, histologic, and scanning electron microscopic analyses were performed at 3 months.

RESULTS

Early lumen gain, late lumen loss, and patent vessel diameter at angiography were not significantly different. Two stent-grafts had significantly more neointima formation (Hemobahn, 9.88 mm(2) +/- 0.94; Wallgraft, 14.98 mm(2) +/- 0.90) than the other stent-graft (Jostent, 6.52 mm(2) +/- 0.46) and the Wallstent (5.24 mm(2) +/- 0.62; P <.01). Patent lumen area was not significantly different (Hemobahn, 42.57 mm(2) +/- 1.41; Jostent, 39.76 mm(2) +/- 2.04; Wallgraft, 40.22 mm(2) +/- 1.04; Wallstent, 41.64 mm(2) +/- 1.59; P =.57). The Hemobahn had significantly more inflammatory reaction (inflammation score of 0.83 +/- 0.03) than the Jostent (0.58 +/- 0.03), Wallgraft (0.55 +/- 0.04), or Wallstent (0.16 +/- 0.01). Angiography and IVUS demonstrated absence of anastomotic neointima formation. Endothelialization was incomplete and immature for all prostheses.

CONCLUSIONS

The stent-grafts caused a greater degree of neointima formation and inflammatory vessel wall reaction than the bare stent. However, these changes did not interfere with patent lumen areas and occurred in the absence of excessive anastomotic neointima formation.

Results of the Jostent coronary stent graft implantation in various clinical settings: procedural and follow-up results

The Jostent coronary stent graft (CSG) is composed of a PTFE layer sandwiched between two stainless steel stents, initially introduced for the treatment of coronary perforations and aneurysms with excellent results. By providing a mechanical barrier, this stent design also may be beneficial in the treatment of complex ulcerated lesions and in-stent restenosis by preventing debris protrusion and neointimal proliferation through the stent struts. To evaluate the safety and efficacy of this stent graft, we implanted 78 CSGs in 70 patients for a broad range of indications, including coronary perforations, aneurysms, degenerated saphenous vein grafts, complex lesions, and in-stent restenosis. The primary angiographic success rate (95.9%) was high, and using intravascular ultrasound (IVUS) guidance during stent implantation and high inflation pressures (19.3 +/- 3.2 atm), stent expansion with optimal symmetry was achieved in 94.7%. One limitation of the Jostent CSG was the side-branch occlusion rate (18.6%) and the resulting non-Q-wave infarction rate in seven cases (mean CK elevation, 238 U/l), acute Q-wave MI in two cases, and transient ventricular fibrillation in one patient after occlusion of the proximal RCA side branch without further complications. Subacute stent thrombosis occurred in four cases (5.7%) 7 to 70 days after stent implantation, despite using combined antiplatelet therapy with aspirin (ASA), ticlopidine, and/or clopidogrel for 30 days. Angiographic follow-up was available in 56 patients (80.0%) after a mean of 159 +/- 49 days, and follow-up IVUS was available in 38 cases. The overall restenosis rate (> 50% diameter stenosis) was 31.6% manifest primarily as edge restenosis (29.8% stent edge vs. 8.8% stent center; P < 0.001). IVUS examinations showed a minimal late lumen loss of 0.4 +/- 2.2 mm(2) within the center of the stent graft vs. 3.2 +/- 2.3 mm(2) at the stent edges (P < 0.001). The restenosis rate in the prespecified subgroups was 33.3% for saphenous vein grafts (2/6 lesions), 30.0% in complex lesions (6/20 lesions), and 38.5% (10/26 lesions) for the treatment of in-stent restenosis. Implantation of the Jostent CSG is feasible and safe, even in complex lesion subsets, and is associated with high primary success rates provided major side branches are avoided. The use of this stent may require an extended time course of antiplatelet therapy. Frequent focal stent edge renarrowing influences the overall restenosis rate. However, in treatment of complex in-stent restenosis and vein graft lesions, stent grafts may offer benefit over conventional therapies. Covered stents such as the JoMed coronary stent graft may become essential for bailout treatment of coronary perforations.

Successful concomitant treatment of a coronary-to-pulmonary artery fistula and a left anterior descending artery stenosis using a single covered stent graft: a case report and literature review

This report describes a case of a 47-year-old man who presented with early post-Q wave myocardial infarction angina and an atherosclerotic left anterior descending stenosis associated to a coronary-to-pulmonary artery fistula. Both coronary stenosis and fistula were successfully treated with a single polytetrafluoroethylene-covered stent graft implantation by intravascular ultrasound-guided procedure.

Polytetrafluoroethylene-covered stent and coronary artery aneurysms

Angiographically detected coronary aneurysms (i.e., coronary segment greater then 1.5 times the normal artery) have an incidence of 0.3%-4.9% among patients undergoing coronary angiography and have been reported after an intervention procedure with a frequency of 2%-10%. The indication for treatment and the best modality still need to be defined. Some authors reported the successful treatment of coronary aneurysms with the polytetrafluoroethylene (PTFE)-covered stent implantation, supporting the role of this strategy. In our institution, from September 1997 to December 1999 eight PTFE-covered stents were implanted to treat seven coronary aneurysms in seven patients. All aneurysms were successfully treated by the PTFE-covered stent. In one case, there was the necessity of an additional PTFE stent to cover the aneurysm completely. In no case did the loss of stent occur. No in-hospital MACE occurred. At 35 +/- 8 (21-44) months, six patients were symptom-free. Angiographic follow-up was performed in all patients at 10 +/- 6 months. Restenosis occurred in one patient (14%) who had repeat percutaneous coronary interventions. This preliminary experience suggests that PTFE-covered stent may be useful in the treatment of coronary artery aneurysms.

Successful long-term therapy following saphenous vein-covered stent deployment for atherosclerotic coronary aneurysm

We describe a case of atherosclerotic aneurysm involving the left main coronary artery in a patient with prior coronary artery bypass surgery. A saphenous vein-covered stent was used to seal the aneurysm in conjunction with conventional stenting of an associated native vessel coronary stenosis. Focal late restenosis involving the stent graft was successfully treated with repeat angioplasty and brachytherapy. Autologous vein-covered stent deployment should be considered in the treatment of symptomatic or progressively enlarging coronary aneurysms.

The polytetrafluoroethylene-covered stent: a device with multiple potential advantages

The polytetrafluoroethylene (PTFE)-covered stent has emerged in the past year as a device with multiple potential advantages. Its structure (a sandwich composed of a layer of PTFE membrane between two stents) makes this the ideal tool for treating coronary ruptures, and for excluding coronary aneurysms. Furthermore, this device may be useful in the treatment of aortocoronary vein graft stenosis. In the present review, the authors summarize experiences with covered stents, and focus attention on available data on the implantation of PTFE-covered stents in human beings to treat coronary ruptures, aneurysms and aortocoronary vein graft stenosis.

Treatment of traumatic aneurysms and arteriovenous fistulas of the skull base by using endovascular stents

OBJECT

The authors describe their preliminary clinical experience with the use of endovascular stents in the treatment of traumatic vascular lesions of the skull base region. Because adequate distal exposure and direct surgical repair of these lesions are not often possible, conventional treatment has been deliberate arterial occlusion. The purpose of this report is to demonstrate the safety and efficacy as well as limitations of endovascular stent placement in the management of craniocervical arterial injuries.

METHODS

Six patients with vascular injuries were treated using endovascular stents. There were two arteriovenous fistulas and two pseudoaneurysms of the distal extracranial internal carotid or vertebral arteries resulting from penetrating trauma, and two petrous carotid pseudoaneurysms associated with basal skull fractures. In one patient a porous stent placement procedure was undertaken as well as coil occlusion of an aneurysm, whereas in the remaining five patients covered stent grafts were used as definitive treatment. There were no procedural complications. One patient in whom there was extensive traumatic arterial dissection was found to have asymptomatic stent thrombosis when angiography was repeated 1 week postoperatively. This was the only patient whose associated injuries precluded routine antithrombotic or antiplatelet therapy. Follow-up examinations in the remaining five patients included standard angiography (four patients) or computerized tomography angiography (one patient), which were performed 3 to 6 months postoperatively, and clinical assessments ranging from 3 months to 1 year in duration (mean 9 months). In all five cases the vascular injury was successfully treated and the parent artery remained widely patent. No patient experienced aneurysm recurrence or hemorrhage, and there were no thromboembolic complications.

CONCLUSIONS

The authors' experience demonstrates that endovascular treatment of traumatic vascular lesions of the skull base region is both feasible and safe. The advantages of minimally invasive stent placement and parent artery preservation make this procedure for repair of neurovascular injuries a potentially important addition to existing methods.

Membrane-covered stents: a new treatment strategy for saphenous vein graft lesions

The restenosis rate after stenting of lesions in aortocoronary venous bypass grafts still has to be considered unsatisfactorily high. We investigated a new stent design characterized by an expandable polytetrafluorethylene (PTFE) membrane in between two layers of struts. Five consecutive male patients (age 70 +/- 6 years) were followed prospectively who presented with at least two de novo lesions in different grafts 13 +/- 3 years after bypass surgery. A total of 11 lesions were treated located in grafts anastomosed to the circumflex (n = 3), to the LAD (n = 7), and to the right coronary artery (n = 1). Within the same procedure, every patient received membrane-covered stents (n = 6) and conventional stents (n = 5) in either of their lesions. All patients underwent successful interventions. The minimal luminal diameter increased from 1.0 +/- 0.5 to 2.9 +/- 0.6 mm in lesions treated by the membrane-covered stents and from 0.8 +/- 0.4 to 2.4 +/- 0.7 mm in the lesions treated by conventional stents. During follow-up, four out of five patients required angioplasty for in-stent restenosis of lesions covered by a conventional stent, whereas no patient underwent revascularization for a lesion treated by a membrane-covered device. The mean minimal luminal diameter of lesions covered by a conventional stent decreased by 42% to 1.4 +/- 0.6 mm; the mean minimal luminal diameter of the lesions treated by a stent graft declined by 9% to 2.8 +/- 0.6 mm (P < 0.05). This series of intraindividual comparisons suggests that membrane-covered stents may have the power to reduce in-stent restenosis in obstructed aortocoronary venous bypass grafts.

Emergency polytetrafluoroethylene-covered stent implantation to treat coronary ruptures

BACKGROUND

Coronary perforation is a life-threatening complication of percutaneous interventions. In the past few years, the implantation of covered stents has emerged as a strategy for treatment when the traditional conservative approach (ie, prolonged balloon inflation and reversal of anticoagulation) fails.

METHODS AND RESULTS

Since May 1997 (when polytetrafluoroethylene [PTFE]-covered stents were available at our institutions), 11 of the 12 consecutive patients who had coronary ruptures that were unsuccessfully sealed with prolonged balloon inflation and reversal of anticoagulation were treated with 12 PTFE-covered stents (PTFE group). The efficacy of the PTFE-covered stent was compared with that of noncovered stents, which were used to treat 17 perforations (non-PTFE group). One patient sustained a very distal perforation that was not suitable for covered stent sealing and underwent emergency surgery. All vessel ruptures treated with PTFE-covered stent implantation were successfully sealed. The time necessary to deploy the stent was 10+/-3 minutes (range, 4 to 15 minutes). All patients but one were discharged from the hospital and had an optimal early clinical outcome. One patient underwent emergency bypass surgery and died in the intensive care unit. The occurrence of cardiac tamponade and the necessity for emergency surgery was significantly lower in the PTFE group than in the non-PTFE group. At 14+/-4 months, the 10 discharged patients had not experienced any major adverse cardiac events.

CONCLUSIONS

This preliminary study supports the utility of the PTFE-covered stent for the nonsurgical treatment of vessel ruptures.

Treatment of aortocoronary vein graft lesions with membrane-covered stents: A multicenter surveillance trial

BACKGROUND

Stent implantation in lesions of degenerated aortocoronary vein grafts is associated with a high risk of periprocedural thrombus embolization and in-stent restenosis.

METHODS AND RESULTS

In a multicenter study, we followed up 109 consecutive patients (mean age 66+/-8 years, 12% female) who received polytetrafluoroethylene (PTFE) membrane-covered stents for 125 de novo stenoses in vein grafts 11+/-5 years after bypass surgery. Stent deployment was successful in all but 1 patient; 1 patient suffered from subacute stent thrombosis. Six-month cardiac mortality was 7% (8 patients), 3 patients (3%) underwent repeat bypass surgery, and 9 patients (8%) required target-lesion PTCA. Repeat angiography revealed vessel occlusions in 9% and in-stent restenosis in 8% of patients by the end of follow-up.

CONCLUSIONS

Membrane-covered stents appear to be a safe and efficient treatment strategy associated with a low incidence of restenosis and target-vessel revascularization. Compared with previous studies, the investigated device is not associated with an increase in mortality or late vessel occlusions.

Polytetrafluoroethylene-covered stent for the treatment of narrowings in aorticocoronary saphenous vein grafts

We compared the outcome of patients with saphenous graft disease treated with polytetrafluoroethylene (PTFE)-covered stents or noncovered stents. Angiographic success was similar; non-Q-wave myocardial infarction was lower in the PTFE group (p = 0.06) and long-term major cardiac events and restenosis rate were similar in the 2 groups. Implantation of PTFE-covered stent in vein graft disease seems to reduce the occurrence of distal embolization.

Membrane-covered stents for the treatment of aortocoronary vein graft disease

We report of a 78-year-old patient who underwent angioplasty for two de novo lesions in different aortocoronary venous bypass grafts. Whereas one lesion was treated by conventional stents, two adjacent lesions in a second bypass graft were covered by two newly designed stents with a polytetrafluorethylene (PTFE) membrane in between two layers of struts. The patient was first readmitted at month 5 with recurrent angina pectoris. High-grade in-stent restenosis of the lesion covered by the conventional stent was diagnosed, whereas the lesions treated by the membrane-covered stent revealed no restenosis. The patient underwent subsequent balloon angioplasty and was readmitted with unstable angina 8 months after the initial procedure. The angiogram revealed subtotal occlusion of the vein graft due to diffuse in-stent restenosis within the conventional stent. Undergoing re-PTCA, the patient received an additional membrane-covered stent placed over the proximal device. For the following 7 months, the patient stayed asymptomatic and underwent elective reangiography, which revealed a satisfying long-term result with no relevant luminal loss at the target site. This intraindividual comparison of stents in aortocoronary vein grafts suggests that PTFE membrane-covered stents might reduce restenosis as compared to conventional stents in venous bypass grafts. Furthermore, these stents potentially represent a new treatment strategy to fight in-stent restenosis in selected lesions.

Unsuccessful long-term outcome after treatment of a vein graft false aneurysm with a polytetrafluoethylene-coated Jostent

We describe a case in which a stented ulcerated plaque in an old vein graft ruptured to a huge false aneurysm. By the use of a PTFE-coated Jostent, the false aneurysm could be percutaneously closed. However, 6 months later, a new false aneurysm, probably due to focal perforation of the covered Jostent, developed.