Role of angioplasty in patients with previous coronary artery bypass surgery

Coronary artery and saphenous vein graft remodeling: a review of histologic findings after various interventional procedures--Part V

Catheter balloon angioplasty is a well accepted form of nonsurgical treatment of acutely and chronically obstructed coronary artery vessels. It is also the centerpiece for various new intervention techniques. Their morphologic effect on the site of obstruction has been termed "remodeling." Part V of this six-part series focuses on remodeling effects of balloon angioplasty on obstructed young (< or = 1 year) and old (> 1 year) saphenous vein bypass grafts.

Post-stenting enlarging false aneurysm of a saphenous vein graft

Stenting seems to be a definitive procedure after failed balloon coronary angioplasty. This report describes a case of redo coronary bypass grafting and concomitant resection of enlarging false aneurysm of a saphenous vein graft that developed secondary to stenting for recurrent stenosis after serial percutaneous transluminal coronary angioplasty. It warns us of a pitfall in catheter intervention in an aged saphenous vein graft.

Percutaneous revascularization of ostial saphenous vein graft stenoses

OBJECTIVES

This study sought to evaluate the short-term results and long-term outcome of percutaneous revascularization of ostial saphenous vein graft stenoses in a large patient series.

BACKGROUND

Previous studies have demonstrated that the results of balloon angioplasty for native coronary ostial stenoses are significantly worse than those for nonostial lesions. However, it is controversial whether interventions in patients with ostial saphenous vein grafts carry a similar prognosis.

METHODS

We identified 68 consecutive patients with ostial (group I) and 72 consecutive patients with proximal, nonostial (group II) saphenous vein graft stenoses who underwent percutaneous angioplasty or directional atherectomy for a single new stenosis at the Cleveland Clinic between 1986 and 1992.

RESULTS

Success was achieved in 61 patients (89.7%) in group I and 64 (88.9%) in group II (p = 0.88). There were no differences in major procedural complications (death, Q wave infarction and bypass surgery) between the two groups. At a mean (+/- SD) follow-up of 23 +/- 17 months, 36 patients (64%) in group I had one or more adverse events (death, infarction, repeat coronary revascularization or cardiac-related hospital admission) compared with 34 patients (58%) in group II (p = 0.87). Twenty-eight patients (50%) were angina free in group I compared with 33 (56%) in group II (p = 0.65). During the follow-up period in group I, 7 patients died (13%), 10 had a myocardial infarction (18%), 11 had repeat bypass surgery (20%), 8 had repeat percutaneous interventions (14%), and 30 had one or more cardiac-related hospital admissions (54%). The incidence of these events was similar in group II except for a slightly higher incidence of myocardial infarction: 6 patients died (10%), 3 had a myocardial infarction (5%), 12 had repeat bypass surgery (20%), 12 had repeat percutaneous interventions (20%), and 26 had one or more cardiac-related hospital admissions (44%).

CONCLUSIONS

Unlike ostial native coronary disease, the clinical, procedural and follow-up profile of ostial saphenous vein graft revascularization is not significantly worse than proximal nonostial disease. This finding may be related to the overall suboptimal results of percutaneous revascularization in saphenous vein grafts compared with native coronary arteries or to the unfavorable intrinsic properties of ostial native coronary arteries compared with ostial vein grafts.

Comparative analysis of saphenous vein bypass vs. native coronary artery balloon angioplasty: technical differences and angiographic response

To evaluate technical differences and angiographic response of saphenous vein bypass graft angioplasty in comparison to native coronary arteries, we retrospectively analyzed 54 patients undergoing this procedure at The Toronto Hospital between February 1988 and May 1993. These subjects were temporally matched to a cohort of successful native coronary angioplasties, with comparison of technical parameters, pre-existing qualitative/quantitative (Cardiac Measurement System) stenotic morphology, and angiographic response; including changes in minimum lumen diameter. Saphenous bypass graft angioplasty utilized larger balloons (CABG, 3.27 +/- 0.65 vs. native, 2.90 +/- 0.37 mm, P < .05), and higher inflation pressures (CABG, 10.1 +/- 3.7 vs. native, 8.8 +/- 2.5 atm, P < .05), although in a relative sense, balloon/artery ratios were similar (CABG, 1.09 +/- 0.20 vs. native, 1.03 +/- 0.15, pNS). Pre-procedural bypass graft lesions were more complex, with more frequent ACC/AHA type B1 lesions [CABG, 24/54 (44%) vs. native, 16/54 (30%), P < .05] and luminal thrombus [CABG, 17/54 (31%) vs. native, 6/54 (11%), P < .05]. Quantitative angiography revealed larger "reference" diameters within saphenous veins (CABG, 3.41 +/- 0.76 vs. native, 3.04 +/- 0.51 mm, P < .05), although minimum lumen diameter was less severe (CABG, 0.83 +/- 0.41 vs. native, 0.77 +/- 0.36, P < .05). In terms of balloon angioplasty response, greater improvement in luminal diameter was seen in bypass graft lesions (CABG, 1.55 +/- 0.53 vs. native, 1.32 +/- 0.44 mm, P < .05), with the largest changes within the "body" of the saphenous vein (ostial, 1.53 +/- 0.37; body, 1.68 +/- 0.50; anastomosis, 1.37 +/- 0.57 mm).(ABSTRACT TRUNCATED AT 250 WORDS)

Percutaneous transluminal coronary angioplasty in patients with prior coronary artery bypass grafting: ten years' experience

We evaluated the acute and long-term results of percutaneous transluminal coronary angioplasty in 140 patients with prior coronary artery bypass grafting treated over a 10-year period (1981-1991). Angioplasty was technically successful in 85% of 122 nonoccluded native vessels and in 86% of 50 saphenous vein grafts. Two patients (1.4%) had a myocardial infarction and there were three procedure-related deaths (2.1%). The cumulative probability of survival was 91.5% and 74.5% at 1 and 5 years, respectively. Survival free from myocardial infarction and repeat bypass grafting at 1 and 5 years was 77.3% and 53.9%, respectively. At census, 31% of the 117 survivors were asymptomatic, and 47% were improved by at least two angina grades. Coronary angioplasty provides an apparently safe and effective alternative method of revascularization in selected patients with prior coronary artery bypass grafting. This treatment strategy potentially avoids reoperation with its attendant risks.

Balloon angioplasty for the treatment of lesions in saphenous vein bypass grafts

OBJECTIVES

The purpose of this review is to assess the value and limitations of balloon angioplasty for the treatment of saphenous vein bypass graft obstructions. The potential efficacy of new interventional techniques is discussed.

BACKGROUND

Treatment of ischemia due to saphenous vein bypass graft obstructions poses a difficult problem that will be encountered more often as the pool of surgically treated patients continues to accumulate. Reoperation is technically demanding and is associated with high mortality and morbidity rates. Balloon angioplasty may provide a suitable alternative.

METHODS

The review proposes a classification of patients with attempted saphenous vein graft angioplasty according to expected early and late outcome based on the data obtained from the relevant published data and personal experience.

RESULTS

Angioplasty of a nonocclusive obstruction in a saphenous vein bypass graft has an initial success rate of approximately 90% and is a safe procedure (procedural death rate < 1%, myocardial infarction rate < 4%). The overall average restenosis rate is 42%. Surgical standby is limited and technically difficult. Angioplasty of chronic total occlusions in old grafts is associated with poor initial and long-term results. The long-term clinical results are unfavorable because of the continuing progression of disease in nontreated vein graft segments and native coronary arteries, in addition to the high restenosis rate. New techniques, although promising, have shown neither better initial results nor reduction of restenosis. Stent placement may be useful in longer graft lesions containing friable material.

CONCLUSIONS

Patients may be classified into three groups according to expected early and late outcome on the basis of 1) unfavorable graft anatomy, 2) risk of cardiogenic shock in event of acute graft closure, and 3) age of grafts. The three groups are 1) those with an initial high success, low procedural risk and low restenosis rate; 2) those with an initial high success but high procedural risk and moderate to high restenosis rate; and 3) those with a low success, high risk and high restenosis rate. Balloon angioplasty to treat lesions in venous bypass grafts should be considered a palliative procedure, not a long-term solution, for ongoing progression of coronary artery and vein graft disease. The induced high restenosis rate remains a significant problem.

Emergent saphenous vein graft stenting for acute occlusion during percutaneous transluminal coronary angioplasty

This report describes the initial use in the United States of emergency intravascular stenting for the treatment of acute coronary occlusion complicating elective saphenous vein graft angioplasty. This case adds further support to the role of the balloon expandable stent as an effective "bail out" device for failed angioplasty.

Early postoperative balloon coronary angioplasty for failed coronary artery bypass grafting

In a small number of patients, coronary artery bypass grafting (CABG) fails to relieve anginal symptoms. The usefulness of coronary angioplasty for the treatment of early (less than or equal to 90 days) recurrent ischemia after CABG was examined. Forty-five patients were treated from 2 to 90 days after CABG, including 8 patients studied emergently for prolonged ischemic symptoms. One-, 2- and 3-vessel native disease was found in 4, 10 and 31 patients, respectively. At the time of postoperative angiography, the major anatomic mechanism of recurrent ischemia was complete vein graft occlusion in 12 patients (27%), internal mammary artery occlusion in 3 (7%), vein graft stenoses in 13 (29%), internal mammary artery stenoses in 10 (22%), unbypassed disease in 4 (8%) and disease distal to the graft insertion site in 3 (7%). Angioplasty was successful at 91 of 98 sites (93%), including 95% of 41 lesions in native arteries, 89% of 46 lesions in vein grafts and 100% of 11 internal mammary artery lesions attempted. Complete revascularization was achieved in 84% of patients. There were 2 in-hospital deaths and 2 myocardial infarctions. Two additional patients underwent repeat CABG before discharge after uncomplicated but unsuccessful angioplasty. At late follow-up of the 43 survivors (mean 44 months), there were 4 deaths, 2 of which were noncardiac. Repeat CABG was required in only 3 patients and repeat angioplasty was performed in 10. Angina was absent or minimal in 35 patients; 17 patients were employed full time. Thus, percutaneous transluminal coronary angioplasty can relieve myocardial ischemia after unsuccessful CABG in the majority of patients.

Outcome following emergency coronary artery bypass grafting for failed elective balloon coronary angioplasty in patients with prior coronary bypass

To assess frequency and outcome of emergency coronary artery bypass grafting (CABG) for failed coronary angioplasty in patients with prior CABG, 2,136 elective angioplasty procedures in prior CABG patients were reviewed over a 10-year period. Emergency surgical revascularization was required in 19 patients (0.9%) with prior CABG, compared with 130 of 6,974 patients (1.9%) without prior CABG (p = 0.001). The interval from the most recent CABG to the failed coronary angioplasty was 6.8 years (range 1 to 16). Referral for emergency CABG was made on the basis of an acute closure not responding to repeat dilatation in 12 native coronary arteries and in 7 saphenous vein grafts. Severe hemodynamic instability after acute closure required the placement of an intraaortic balloon pump in 3 patients, including 2 who required cardiopulmonary resuscitation. A total of 34 saphenous vein grafts and 1 internal mammary artery graft were placed emergently. Three patients with high-risk features (3 prior CABG operations in 1 patient, single remaining vessel to heart in 2 patients) could not be weaned from cardiopulmonary bypass. The remaining 16 patients were discharged after a mean hospital stay of 16 days. Four patients developed new Q waves after CABG. At follow-up (mean 52 months, range 3 to 99), 1 patient died late from an acute myocardial infarction. The 15 survivors had no or mild angina and were free of further CABG. Thus, emergency CABG after failed angioplasty in patients with prior CABG is required infrequently. In patients without extreme high-risk features, emergency repeat CABG can be accomplished with good hospital and long-term results.

Coronary angioplasty for medically refractory unstable angina in patients with prior coronary bypass surgery

Percutaneous transluminal coronary angioplasty (PTCA) has been applied with good results to selected patients with unstable angina and to selected patients who have had prior bypass surgery. The population with prior bypass and unstable angina has not been specifically evaluated. This report reviews the results of angioplasty of 45 vessels in 34 patients with medically refractory unstable angina and at least one prior bypass heart surgery. Of these 34 patients, 32 had rest angina; 14 had resting electrocardiographic changes, all 34 were on aspirin 325 mg QD, 31 were on a calcium blocker, 22 were on a beta blocker, 9 were on intravenous nitroglycerin, and 5 required intraaortic balloon counterpulsation for temporary stabilization. Angioplasty of a vein graft was attempted in 17 patients; the left internal mammary was attempted in 4 patients; 24 native coronary arteries in 15 patients were attempted; 3 of the native arteries were protected left main arteries. Of the LIMA angioplasties, 3 were successful; in the 1 unsuccessful case, the occluded anterior descending artery was opened. Of the 17 vein grafts, 16 were successful: 1 had an acute occlusive syndrome and went to surgery with a balloon pump and bail out catheter; his recovery was uneventful. Of the 24 native artery angioplasties, 22 were successful: one patient was technically unsuccessful in the only vessel attempted; he went to semiemergent surgery and recovered uneventfully. In the other, a right coronary lesion was successfully dilated, but an occluded anterior descending artery was not opened. There were no deaths or in-hospital myocardial infarctions.(ABSTRACT TRUNCATED AT 250 WORDS)