In-hospital and long-term results of stent deployment compared with balloon angioplasty for treatment of narrowing at the saphenous vein graft distal anastomosis site

Contemporary coronary artery bypass graft surgery and subsequent percutaneous revascularization

Patients who have undergone coronary artery bypass graft (CABG) surgery are susceptible to bypass graft failure and progression of native coronary artery disease. Although the saphenous vein graft (SVG) was traditionally the most-used conduit, arterial grafts (including the left and right internal thoracic arteries and the radial artery) have improved patency rates. However, the need for secondary revascularization remains common, and percutaneous coronary intervention (PCI) has become the most common modality of secondary revascularization after CABG surgery. Procedural characteristics and clinical outcomes differ considerably from those associated with PCI in patients without previous CABG surgery, owing to altered coronary anatomy and differences in conduit pathophysiology. In particular, SVG PCI carries an increased risk of complications, and operators are shifting their focus towards embolic protection strategies and complex native-vessel interventions, increasingly using SVGs as conduits to facilitate native-vessel PCI rather than pursuing SVG PCI. In this Review, we discuss the differences in conduit pathophysiology, changes in CABG surgery techniques, and the latest evidence in terms of PCI in patients with previous CABG surgery, with a particular emphasis on safety and long-term efficacy. We explore the subject of contemporary CABG surgery and subsequent percutaneous revascularization in this complex patient population.

Optimal revascularization strategies for percutaneous coronary intervention of distal anastomotic lesions after coronary artery bypass surgery

OBJECTIVE

To determine the best revascularization strategy when treating distal anastomotic lesions.

BACKGROUND

Distal anastomotic lesions are the most common reason for venous graft failure especially early after bypass surgery. However, the best percutaneous method for treating these lesions is still controversial.

METHODS

All patients from 2/2000 to 1/2011 who underwent percutaneous coronary intervention of bypass graft distal anastomotic lesions were retrospectively enrolled. Among the 139 patients included, 26 (18.7%) were treated with plain old balloon angioplasty (POBA), 68 (48.9%) with bare metal stents (BMS), and 45 (32.4%) with drug-eluting stents (DES).

RESULTS

Baseline characteristics were generally comparable among the 3 groups. At 6 months' follow-up, the highest rate of target lesion revascularization-major adverse cardiac events (TLR-MACE) was seen in the BMS group compared to the DES and POBA groups (16.2 vs. 2.2 vs. 3.8%, respectively, P=0.03), which was driven mainly by the highest rates of death and TLR in the BMS group (11.8 and 4.7%, respectively). At 1-year follow-up, a higher rate of TLR-MACE was seen in the BMS group compared to the DES and POBA groups (20.6 vs. 11.1 vs. 7.7%, respectively, P=0.19). After adjustment, on Cox regression analysis for hazard ratios, no significant differences were found among the 3 groups at 1-year follow-up of TLR-MACE.

CONCLUSIONS

When selecting the treatment modality for saphenous vein graft distal anastomotic lesions, BMS implantation should be discouraged while POBA and DES implantation can be performed with favorable long-term outcomes. The optimal treatment approach should be evaluated in large, randomized clinical trials.

Distal anastomotic lesions after coronary artery bypass surgery: incidence, pathogenesis, and treatment approach

Distal anastomotic lesions are the most common reason for venous and arterial graft failure. Redo coronary artery bypass surgery carries a higher risk for mortality and non-fatal myocardial infarction. Many operators therefore consider percutaneous coronary intervention as a good alternative for relieving angina symptoms in this subset of patients with anastomotic lesions. However, the best percutaneous method for treating these lesions is still controversial. Here we review reported data on the incidence, pathogenesis, and treatment of distal anastomotic lesions in both venous and arterial bypass grafts.

Endovascular stenting of an extracranial-intracranial saphenous vein high-flow bypass graft: Technical case report

Background:

The authors describe a case of endovascular stenting of an extracranial–intracranial saphenous vein high-flow bypass graft in the management of a complex bilateral carotid aneurysm case.

Case Description:

A 43-year-old woman was admitted with progressive visual field restriction and headache. Imaging studies revealed bilateral supraclinoid carotid aneurysms. The right carotid aneurysm was clipped and the left one was treated by an endovascular procedure, after performing an internal carotid artery–middle cerebral artery (ICA-MCA) saphenous vein bypass graft. A few months following the bypass procedure, a 70–80% stenosis of the graft was discovered and treated endovascularly with a stenting procedure. Follow-up at 36 months after the first operation showed the patency of the venous graft and no neurological deficits.

Conclusions:

Endovascular stenting of the extracranial–intracranial saphenous vein high-flow bypass graft is technically feasible when postoperative graft occlusion is discovered.

Endovascular Management of Symptomatic Spasm of Radial Artery Bypass Graft

OBJECTIVE

To describe the technique of endovascular access for treatment of vasospasm of a radial artery bypass graft from the occipital artery to the M3 branch of the middle cerebral artery (MCA) in a patient with moyamoya disease.

CLINICAL PRESENTATION

A 32-year-old woman presented with recurrent right-sided ischemic symptoms in the territory of a previous stroke. Angiographic findings were consistent with moyamoya disease, and a perfusion deficit was identified on computed tomography (CT) perfusion imaging.

TECHNIQUE

The patient underwent a left MCA bypass graft for flow augmentation. She returned with an occluded bypass graft, collateralization of the anterior MCA territory through a spontaneous synangiosis, and a severe perfusion deficit in the posterior MCA territory. She underwent a revision bypass graft procedure with the radial artery from the occipital artery stump to the MCA-M3 branch. She developed repeated symptomatic vasospasm of the radial artery graft postoperatively. After systemic anticoagulation, the graft was accessed through the occipital artery, and intra-arterial verapamil was injected. When this failed to resolve the graft spasm, the radial artery graft was accessed with a 0.14-inch Synchro-2 microwire (Boston Scientific, Natick Massachusetts), and sequential angioplasties were performed using over-the-wire balloons from the proximal to distal anastomosis and in the occipital artery stump. A nitroglycerin patch was applied cutaneously over the graft to relieve the vasospasm.

RESULTS

No complications occurred. Graft patency with robust flow was observed on the 5-month follow-up angiogram.

CONCLUSION

Endovascular techniques can be safely used for salvage of spastic extracranial-intracranial grafts.

A comparison of the radial and the femoral approach in vein graft PCI. A retrospective study

BACKGROUND

Transradial PCI is a safe and effective method of percutaneous revascularization. However, there is limited data on the efficacy of the transradial approach for saphenous vein graft (SVG) PCI.

METHODS

We studied 334 patients who underwent SVG PCI between January 2000 and December 2003, and compared the radial (132 patients) and the femoral (202 patients) approach.

RESULTS

Mean EF (55.6+/-18.6% radial versus 58.1+/-16.8% femoral), lesion location (proximal, mid, distal: 22.6/50.6/26.7% versus 22.6/44.5/32.9% respectively) and lesion type (B1/B2/C: 3.4/4.1/92.5% versus 0.4/3.1/96.5%) were similar in both groups (P>0.05). Five patients had a failed radial attempt (3.8%) and were switched to the femoral approach. Mean fluoroscopy time (20.4+/-12.2 versus 18.4+/-10.2 min), procedural time (60.0+/-27.2 versus 61.6+/-24.9 min) and the use of contrast (223+/-91 versus 234+/-91 ml) IIB/IIIA inhibitors (27.2 versus 33.2%), and stenting (81.5 versus 81.3%) were similar in both groups, whereas 5 or 6 French sheaths were used more often in the radial group (83.4 versus 64.9%, P<0.01). Angiographic success (93.9 versus 92.9%), in hospital MACE (radial:5 MI (3.8%) versus femoral: 1 death (0.5%) and 7 MI (3.5%) and major vascular complications (0.7 versus 0.5%) were also similar.

CONCLUSIONS

The radial approach in SVG PCI is as fast and successful as the femoral.

Successful angioplasty and stenting of bilateral internal mammary artery grafts from the left radial approach. Case report and review of the literature

We describe a case of successful percutaneous transluminal coronary angioplasty and stenting from the left radial approach in a patient with effort angina due to two tight stenoses at the distal anastomosis site of the internal mammary artery grafts. The left radial approach has several advantages compared with the conventional femoral approach: a lower rate of vascular complications and an easier vascular access to the left internal mammary artery graft. The distance from the access site to the origin of the artery is shorter and involves less angulation than the femoral approach. The radial approach is not only safe but it enables faster patient mobilisation and seems also useful in reducing management costs with a hospital stay that can be reduced to 6 h in low-risk cases.

Evidence based medicine: role of multidetector CT in the follow-up of patients receiving coronary artery bypass graft

PURPOSE

The aim of this study was to define the role of multidetector computed tomography (MDCT) in the follow-up assessment of patients undergoing coronary artery bypass grafting (CABG) using an evidence-based medicine (EBM) approach.

MATERIALS AND METHODS

We performed a literature search of the most reputable studies published in the period 1990-2005 on the clinical follow-up of patients after myocardial revascularisation by CABG. Relevant studies were ranked according to levels of evidence using EBM criteria. A similar search was also conducted on the Internet to identify and review the guidelines posted by the major international scientific societies.

RESULTS

A total of 29 papers meeting the basic reliability requirements of EBM were identified. The reported sensitivity and specificity for electrocardiogram (ECG) testing, stress echocardiography and radionuclide myocardial perfusion imaging were 45% and 82%, 86% and 90%, and 68% and 84%, respectively. All 16 CT studies (one retrospective, the remaining prospective) were validation studies comparing MDCT with conventional coronary angiography. The total number of patients and graft segments studied were 705 and 1,974, respectively. The total number of assessable graft segments were 62%-100%, with a sensitivity and specificity of 75%-100% and 76.9%-100%, respectively.

CONCLUSIONS

The applications of MDCT in the follow-up assessment of patients after CABG are derived from indirect evidence only. The efficacy of the method should be evaluated in randomised clinical trials comparing MDCT not only with conventional coronary angiography but also with other noninvasive stress imaging methods. On the basis of the clinical evidence reported in the literature, the indications for the use of MDCT are still limited. In our view, the completion of such randomised trials combined with the development of new-generation scanners is required to correctly define the role of MDCT in the follow-up assessment of patients who have undergone CABG.

Primary stenting versus primary balloon angioplasty for treating acute myocardial infarction

BACKGROUND

Balloon angioplasty following myocardial infarction (MI) reduces death, non-fatal MI and stroke compared to thrombolytic reperfusion. However up to 50% of patients experience restenosis and 3% to 5% recurrent myocardial infarction. Therefore, primary stenting may offer additional benefits compared to balloon angioplasty in patients with acute myocardial infarction.

OBJECTIVES

To examine whether primary stenting compared to primary balloon angioplasty reduces clinical outcomes in patients with acute myocardial infarction.

SEARCH STRATEGY

We searched MEDLINE, EMBASE, Pascal, Index medicus and The Cochrane Controlled Trials Register (The Cochrane Library) from 1979 to March 2002.

SELECTION CRITERIA

Randomised controlled trials of primary stenting or balloon angioplasty prior to the invasive procedure; intervention in native coronary arteries within 24 hours after onset of symptoms of myocardial infarction; report of death or reinfarction; and follow-up of at least 1 month. Trials were excluded when randomisation occurred after an invasive procedure and if they exclusively included patients with cardiogenic shock.

DATA COLLECTION AND ANALYSIS

Two reviewers independently selected and extracted data from identified trials. Outcomes included mortality, reinfarction, coronary artery bypass grafting, target vessel revascularization, need for vascular repair or blood transfusion. Peto odds ratios were calculated. To explore the stability of the overall treatment effect various sensitivity analyses were performed.

MAIN RESULTS

We included nine trials of 4433 participants. Odds ratios for mortality after stenting compared to balloon angioplasty at 30 days, 6 and 12 months were 1.16 (95% CI 0.78 to 1.73), 1.27 (95% CI 0.89 to 1.83), and 1.06 (95% CI 0.77 to 1.45). At 30 days, 6 and 12 months odds ratios for reinfarction after stenting compared to balloon angioplasty were 0.52 (95% CI 0.31 to 0.87), 0.67 (95% CI 0.45 to 1.00), and 0.67 (95% CI 0.45-0.98) and odds ratio for target vessel revascularization after stenting compared to balloon angioplasty were 0.45 (95%CI 0.34 to 0.60), 0.42 (95% CI 0.35 to 0.51), and 0.47 (95% CI 0.38 to 0.57). The odds ratio for post-interventional bleeding complications after stenting compared to balloon angioplasty was 1.34 (95% CI 0.95 to 1.88; test of heterogeneity p > 0.1).

AUTHORS' CONCLUSIONS

There is no evidence to suggest that primary stenting reduces mortality when compared to balloon angioplasty. Stenting seems to be associated with a reduced risk of reinfarction and target vessel revascularization, but potential confounding due to unbalanced post-interventional antithrombotic/anticoagulant therapies can not be ruled out on basis of this review.

Procedural results and distal embolization after saphenous vein graft stenting and angioplasty for in-stent restenosis of grafts

Saphenous vein graft (SVG) angioplasty is associated with frequent periprocedural complications due to distal embolization and a high risk of restenosis. The purpose of this single-center, retrospective study was to determine the distal embolization incidences and outcomes of stenting for SVG lesions and percutaneous angioplasty for in-stent restenosis of these SVGs. We studied 48 consecutive patients (mean age, 62 +/- 7 years, 92% men) who had prior CABG and underwent stent deployment to SVG lesions detected at our institution over a period of 4 years. Mean lesion length was 12.4 +/- 3.2 mm. The minimal lumen diameter increased from 0.7 +/- 0.3 mm to 3.2 +/- 0.4 mm after stenting. Distal embolization as no reflow/slow flow phenomenon occurred in 5 (10%) patients. Angiographic success was achieved in 98% of the patients. Procedural success was achieved in 96% of the patients. No reflow/slow flow phenomenon was observed, particularly in patients with acute coronary syndrome. During the follow-up, 11 patients (23%) had angiographic evidence of restenosis. Lesions were treated with balloon angioplasty and the minimal lumen diameter increased from 2.6 +/- 1.1 mm to 3.1 +/- 0.3 mm. The angiographic and procedural success rates were both 100%. There were no cases of "no" reflow/slow flow. Restenosis was particularly frequent in patients with diabetes mellitus, hypercholesterolemia, and acute coronary syndrome. Stent implantation in patients with de novo SVG lesions can be achieved with a high rate of angiographic and procedural success. The distal embolization risk is lower during angioplasty of in-stent restenosis lesions of SVGs compared to de novo SVG lesions.

Clinical and angiographic efficacy of a self-expanding nitinol stent in saphenous vein graft atherosclerotic disease: the Stent Comparative Restenosis (SCORES) Saphenous Vein Graft Registry

BACKGROUND

The Stent Comparative Restenosis (SCORES) Saphenous Vein Graft (SVG) Registry was a multicenter, prospective registry designed to evaluate the safety and efficacy of a self-expanding, nickel-titanium (nitinol) stent for de novo SVG lesions.

METHODS

In all, 159 patients with de novo vein graft lesions > or =2.75 and < or =4.25 mm in diameter and <30 mm in length underwent stenting with the Radius self-expanding stent. The primary end point was target vessel failure (TVF) at 9 months, which was defined as a composite of procedural failure, death, myocardial infarction, or target vessel revascularization.

RESULTS

Procedural success was achieved in 96.8% of patients, and the 30-day incidence of major adverse cardiac events was 2.5%. The binary rate of restenosis at 6 months was 28.6%. By 9 months, the rate of TVF was 24.5%, and the rate of major adverse cardiac events was 23.1%. The 9-month Kaplan-Meier survival rates for freedom from TVF and target lesion revascularization were 76.0% and 87.9%, respectively. No clinical or angiographic characteristic was predictive of restenosis.

CONCLUSIONS

In de novo atherosclerotic SVG disease, the use of a self-expanding, nitinol stent was associated with high initial procedural success and favorable early and intermediate outcomes. Because few studies have examined the influence of stent composition and design in SVG disease, these findings not only show the safety and efficacy of this self-expanding stent in de novo SVG disease, but also merit further comparison with balloon-expandable stents.

Comparison of intracoronary gamma radiation for in-stent restenosis in saphenous vein grafts versus native coronary arteries

Intracoronary gamma radiation is effective in reducing recurrent in-stent restenosis (ISR) involving native coronary arteries. This study compares the effectiveness and safety of intracoronary gamma radiation for the treatment of ISR in saphenous vein grafts (SVGs) versus native coronary arteries. In the Washington Radiation for In-Stent restenosis Trial (WRIST) series of gamma radiation trials, 1,142 patients with ISR (230 in SVG and 912 in native coronary arteries) completed 6-month clinical follow-up. All patients underwent balloon angioplasty, atherectomy, and/or restenting. Different ribbon lengths containing 6 to 23 seeds of iridium-192 were used to cover lesion lengths <80 mm. The prescribed radiation doses were 14 or 15 Gy at 2-mm radial distance from the center of the source. Baseline demographics showed that patients with SVGs were older (65 +/- 13 vs 61 +/- 11 years, p <0.001), more likely male (79% vs 64%, p <0.001), had more multivessel coronary disease (81% vs 50%, p <0.001), and less diffuse lesions (17 +/- 10 vs 24 +/- 12 mm, p <0.001). At 6 months, event-free survival was similar for patients with SVG ISR and native coronary ISR (82% vs 84%, p = 0.35). The SVG ISR population had a low rate of late total occlusion (4.6%) and late thrombosis (3.5%). Thus, treatment of ISR with gamma radiation in SVGs had similar outcome to native coronary arteries. The use of gamma radiation for the treatment of ISR should expand to SVGs.

Intravascular gamma radiation for in-stent restenosis in saphenous-vein bypass grafts

BACKGROUND

Intracoronary radiation therapy is effective in reducing the recurrence of in-stent stenosis in native coronary arteries. We examined the effects of intravascular gamma radiation in patients with in-stent restenosis of saphenous-vein bypass grafts.

METHODS

A total of 120 patients with in-stent restenosis in saphenous-vein grafts, the majority of whom had diffuse lesions, underwent balloon angioplasty, atherectomy, additional stenting, or a combination of these procedures. If the intervention was successful, the patients were randomly assigned in a double-blind fashion to intravascular treatment with a ribbon containing either iridium-192 or nonradioactive seeds. The prescribed dose, delivered at a distance of 2 mm from the source, was 14 to 15 Gy in vessels that were 2.5 to 4.0 mm in diameter and 18 Gy in vessels with a diameter that exceeded 4.0 mm. The primary end points were death from cardiac causes, Q-wave myocardial infarction, revascularization of the target vessel, and a composite of these events at 12 months.

RESULTS

Revascularization and radiation therapy were successfully accomplished in all patients. At six months, the restenosis rate was lower in the 60 patients assigned to the iridium-192 group than in the 60 assigned to the placebo group (21 percent vs. 44 percent, P=0.005). At 12 months, the rate of revascularization of the target lesion was 70 percent lower in the iridium-192 group than in the placebo group (17 percent vs. 57 percent, P<0.001), and the rate of major cardiac events was 49 percent lower (32 percent vs. 63 percent, P<0.001).

CONCLUSIONS

The results of our study support the use of gamma-radiation therapy for the treatment of in-stent restenosis in patients with bypass grafts.

Short-term outcome of stent implantation in saphenous vein grafts: predictors of distal embolization and restenosis

The present study, which aimed to determine the predictors of distal embolization and restenosis after stenting for vein graft disease, retrospectively analyzed 51 consecutive patients who underwent stent implantation for diseased saphenous vein grafts. Follow-up angiography was performed 6 months after the procedure and the clinical and angiographic variables were analyzed by multivariate logistic regression to determine the predictors of distal embolization and restenosis. Initial clinical success was achieved in 49 patients, 44 of whom underwent follow-up angiography and were enrolled in the retrospective analysis. Distal embolization occurred in 6 grafts (13.6%). Multivariate analysis showed that the lesion length and the total cholesterol level were independent predictors of distal embolization. Angiographic restenosis occurred in 13 (26.5%) of 49 lesions. The minimum luminal diameter and the percent diameter stenosis after stenting were associated with the occurrence of restenosis. Multivariate analysis of lesions located in the graft body identified graft age as an independent predictor of restenosis. Distal embolization can occur after vein graft stenting, especially in patients with hypercholesterolemia and diffuse stenosis. The post-stenting minimum luminal diameter and the percent diameter stenosis are predictors of restenosis. In particular, graft age is associated with the restenosis of graft body lesions.

Left internal mammary artery graft perforation repair using polytetrafluoroethylene-covered stents

The increase in the use of the left internal mammary artery (LIMA) as graft of choice to the left anterior descending coronary artery for conventional and minimally invasive coronary artery bypass surgery has led to an increased incidence of LIMA pathologic lesions early after surgery. The lesion, commonly located in the body of the LIMA graft, is usually caused by mechanical injury during harvesting of the vessel. In this context, percutaneous intervention with stent implantation can be complicated by vessel rupture, which usually requires emergency surgical repair. We describe two cases of stent implantation in newly placed LIMA grafts complicated by vessel rupture, which were successfully repaired using polytetrafluoroethylene-covered stents.