Late thrombotic occlusion of saphenous vein grafts: successful recanalization using thrombolytic therapy

An embolization containment device

A coaxial catheter system for containment of distal embolization is described. Utilizing a novel 0.014" hypotube with a distal elastomeric occlusion balloon, the PercuSurge GuardWire functions as a guidewire while trapping distal embolization resulting from more proximal intervention. The particulate debris is evacuated with a single operator exchange aspiration catheter (Export catheter) prior to deflation of the distal occlusion balloon. This animal study confirmed the feasibility of concept. The system was easily delivered through tortuous coronary anatomy. The GuardWire served as an adequate rail for delivery of dilatation balloons and a multitude of stents. There was no evidence of deep wall damage from low-pressure inflation and apposition of the distal occlusion balloon.

Long-term angiographic follow-up of occluded saphenous bypass grafts treated with prolonged urokinase infusion

We report on 10 occluded saphenous vein bypass grafts in nine patients treated with prolonged urokinase infusion. Our purpose was to evaluate the patency of these grafts during long-term follow-up. We retrospectively analyzed consecutive patients treated at a single center. All patients had angiography 0.25 to 54 months after treatment. Results indicated that clot lysis was achieved in all grafts with urokinase infusions of 1,790,000 to 25,920,000 units given over 17 to 108 hours. In two grafts there was no filling of the distal native vessel and in one, a 50% stenosis with ulceration remained. There was a progressive loss of graft patency over the first 18 months, but 50% of the grafts that were opened with prolonged urokinase infusion remain patent. Long-term patency depends upon successful opening without residual obstruction and with good flow into the distal native vessel.

Recanalization of totally occluded saphenous vein grafts using local urokinase delivery with the Dispatch catheter

Current techniques for the percutaneous revascularization of totally occluded vein grafts are limited by a low initial success rate, a significant incidence of distal embolization, and a high rate of early graft reclosure. This case report describes two patients in whom graft recanalization was attempted with the combined use of balloon angioplasty/intra-graft stent placement and local urokinase delivery using a new angiotherapy catheter. Successful recanalization was achieved in both patients without major complications, in spite of a large thrombus burden as demonstrated by angiography.

Initial and long-term outcome of 83 patients after balloon angioplasty of totally occluded bypass grafts

OBJECTIVES

This study was designed to evaluate the safety and short- and long-term results of coronary angioplasty of totally occluded bypass grafts in patients with clinical conditions other than acute myocardial infarction.

BACKGROUND

Total occlusion of bypass grafts after coronary artery surgery often causes recurrent ischemia. The safety and results of percutaneous transluminal coronary angioplasty in occluded bypass grafts are controversial.

METHODS

All patients with dilation of a totally occluded bypass graft attempted between 1981 and 1991 were retrospectively identified from a data base. Patients treated in the setting of an acute myocardial infarction were excluded. Eighty-three patients met these criteria and constitute the study group. Hospital records, office charts and procedural reports were reviewed in all patients to supplement details available in the data base.

RESULTS

The time from bypass surgery to attempted coronary angioplasty ranged from 1 to 226 months (mean time 88 months). The mean (+/- SD) duration of graft occlusion was 31 +/- 46 days (range 1 to 180). In 27 attempts the bypass graft was the only site dilated, and in 56 attempts (68%) one to six other sites (n = 101) were dilated. Angiographic success (< or = 40% residual lumen stenosis) was achieved in 61 grafts (73%) and 98 of the additional sites (97%) (p < 0.001). Major complications included one procedural death and two Q wave infarctions. Follow-up for a mean of 32 months demonstrated a 1- and 3-year actuarial survival rate of 94% and 80%, respectively. At 3 years, only 34% of patients were free of repeat angioplasty or surgery.

CONCLUSIONS

Angioplasty of totally occluded bypass grafts can be successful in the majority of selected patients, although major complications can occur. Strategies for sustained patency are needed to improve the long-term results.

Intracerebral hemorrhage complicating urokinase infusion into an occluded aortocoronary bypass graft

Selective infusion of urokinase into occluded coronary bypass vein grafts is effective in restoring patency. We report the occurrence of intracerebral hemorrhage complicating an intra-graft urokinase infusion protocol. The patient had known cerebral vascular structural pathology without recent clinical complications. Caution with the use of thrombolysis in this setting is suggested.

Prolonged intragraft urokinase with a new infusion wire: improved short-term results

Patients with aged saphenous vein grafts and recurrent symptoms of angina are being seen with increasing frequency [Bourassa: J Am Coll Cardiol 17:1081-1083, 1991]. The treatment of these patients remains a dilemma. Direct balloon angioplasty is frequently complicated by distal embolization and early restenosis [Aureran and Gruentzig: Am J Cardiol 53:953-954, 1984]. There is evidence that thrombus plays a significant role in this occlusive process [Hartmann et al.: J Am Coll Cardiol 18:1517-1523, 1991]. Prolonged intragraft urokinase infusion with a new multiside hole infusion catheter debulks thrombus and permits balloon angioplasty without the usual complications.

New treatment approach for chronic total occlusions of saphenous vein grafts: thrombolysis and intravascular stents

Balloon dilation of saphenous vein graft (SVG) occlusions has a lower success rate than angioplasty of native coronary arteries. To improve this outcome, a new therapy for chronic total SVG occlusions was developed. In three aortocoronary bypass graft patients with class III-IV angina and chronic occlusion of the SVGs to the left anterior descending artery (age of occlusions: 2-24 wk, age of graft 1-13 yr), standard recanalization was achieved with a guide wire and intracoronary urokinase infusion (0.5-1.0 million unit bolus followed by 100,000 IU/hr for 11-24 hr; mean infusion time: 19.7 hr). In each patient, a residual focal stenosis (average 82.5%) was successfully dilated and stented (single 4.0 mm Palmaz-Schatz in two patients and a 3.5 mm Strecker stent in the other). All patients had complete relief of symptoms and no sequelae. During a mean 7.7 mon follow-up, 6-mon arteriographic evaluation in two patients showed minimal intra-stent narrowing (26% and 34%). In the Strecker stent patient, the device proved too small for the vein graft, leading to an 89% stent stenosis found on follow-up arteriography at 5 mon. The stent was redilated successfully with a 5% residual narrowing. After urokinase recanalization of chronic total SVG occlusions, intravascular stents may improve the long-term results seen with conventional SVG angioplasty.

Acute myocardial infarction complicating urokinase infusion for total saphenous vein graft occlusion

Saphenous vein graft occlusions have been successfully treated with extended urokinase infusions. We report a case of myocardial infarction complicating this treatment. A review of reported cases suggests that this complication may not be uncommon. The optional drug, dose, and infusion technique for intra-graft lytic therapy has not been determined. The costs, risks, and difficulty of this technique may limit its application.

Prolonged intravenous urokinase infusion: an alternative pharmacologic approach in the treatment of thrombus-containing saphenous vein graft stenoses

A subtotally occlusive saphenous vein graft stenosis resolved after rapid intracoronary and prolonged intravenous urokinase infusion. Additional therapy was unnecessary, avoiding the attendant risks of saphenous vein graft angioplasty. Combined intracoronary and intravenous urokinase infusion should be considered prior to coronary angioplasty of saphenous vein graft stenoses, particularly when diffuse degeneration is present or the risk of underlying thrombus is high.

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.

Mechanism of acute myocardial infarction in patients with prior coronary artery bypass grafting and therapeutic implications

Although acute myocardial infarction (AMI) is usually due to thrombotic occlusion when involving a native coronary artery, the mechanism responsible for AMI in patients with previous coronary artery bypass grafting (CABG) is not well understood. Since knowledge of pathophysiology of AMI may alter subsequent management, angiograms obtained between 1 hour and 7 days of AMI (median 1 day) were reviewed in 50 patients greater than 1 year after CABG. The culprit vessel was identified by the presence of residual stenosis and/or thrombus in the vessel supplying the infarct zone or by reviewing previous angiograms. The infarct vessel was identified as a vein graft in 38 (76%) patients, the native vessel in 8 patients (16%) and could not be accurately determined in 4 patients (8%). Among the 38 vein grafts suspected as the infarct vessel, unequivocal angiographic evidence of residual thrombus (filling defect/persistent staining) was present in 31 (82%) and was greater than 2 cm in length in 15 patients. Successful reperfusion occurred in only 2 of 8 (25%) grafts after intravenous thrombolytic therapy. Intragraft thrombolysis with or without additional angioplasty was successful at restoring flow in 8 of 10 (80%) grafts. Data indicate that in patients who have undergone previous CABG, AMI is usually caused by thrombotic occlusion of a saphenous vein graft and that conventional intravenous thrombolytic therapy may be inadequate to restore flow. The large mass of thrombus and absent flow in the graft may require subselective drug infusion, a higher thrombolytic dose or a mechanical means of recanalization.

Nonacute thrombolytic therapy: an adjunct to coronary angioplasty in patients with large intravascular thrombi

The presence of intravascular thrombus can make coronary angioplasty difficult or impossible to perform. To determine if thrombolytic agents could lyse large, nonacute thrombi, we retrospectively analyzed the angiograms of all 14 patients with unstable angina and large intravascular thrombi (greater than 2 cm in length) who were treated with thrombolytic agents at The Johns Hopkins Hospital between October 1987 and April 1989. Twelve patients were treated with intracoronary streptokinase, and two with intravenous tissue plasminogen activator. Coronary arteriography was repeated immediately after treatment and a mean of 1.6 +/- 0.3 days later. The degree of thrombolysis and change in distal vessel perfusion was evaluated. Thrombolysis was graded as considerable if there was greater than 75% resolution of apparent thrombus, and as complete if no stenosis or only a discrete residual stenosis was apparent. Fifty-seven percent of patients ultimately achieved considerable or complete thrombolysis and were able to undergo successful angioplasty. Patients achieving considerable or complete thrombolysis had a 28 +/- 7% increase in luminal diameter and demonstrated normalization of initially absent distal perfusion, except for the one patient who had normal distal flow prior to treatment. A maximal thrombolytic effect was evident only at the time of "delayed" angiography in all patients who responded to treatment and underwent both follow-up arteriograms. We conclude that thrombolytic agents can effectively lyse large, nonacute intravascular thrombi, thereby facilitating coronary angioplasty. A full thrombolytic effect does not occur for hours to days after drug administration, and may not become evident unless delayed angiography is performed.

A complication of prolonged urokinase infusion into a chronically occluded aortocoronary saphenous vein graft

Recanalization of a chronically occluded aortocoronary saphenous vein graft was performed, using a prolonged intracoronary infusion of urokinase followed by percutaneous transluminal coronary angioplasty (PTCA). Despite an angiographically successful result, the patient developed acute myocardial infarction, presumably secondary to distal migration of partially lysed thrombus. One week after successful angioplasty, the graft was once again proximally occluded.