Saphenous vein graft intervention

DR GOPI KRISHNANIMS,HYDERABAD,INDIA.

• Svg pathology.• Natural course.• Problems in interventions.• Techniques.• Procedure related complications.• Role of stents and supportive medications.

Patients who experience recurrence of ischemia after CABG

lesions in– saphenous vein graft (SVG).– native arteries.– internal mammary. – Radial.– gastroepiploic graft.– proximal subclavian artery.

Early postoperative ischemia (<1 month):

• acute vein graft thrombosis (60%). • incomplete surgical revascularization (10%).• kinked grafts.• focal stenoses distal to the insertion site and

at the proximal or distal anastomotic sites.• spasm or injury.• insertion of graft to a vein causing AV fistula. • bypass of the wrong vessel. • all above cxs are common after minimally invasive and “off-bypass” techniques)

Early postoperative ischemia (1 month–1 year):

• peri-anastomotic stenosis.• graft occlusion.• mid-SVG stenosis from fibrous intimal

hyperplasia.• Recurrence of angina at about three months

postoperatively is highly suggestive of a distal graft anastomotic lesion and in most cases, lead to evaluation for PCI

Late postoperative ischemia (>3 years after surgery):

• the most common cause of ischemia is the formation of new atherosclerotic plaques which contain– foam cells,– cholesterol crystals,– blood elements, – necrotic debris as in native vessels.

• However, these plaque have less fibrocollagenous tissue and calcifi cation, so they are softer, more friable, of larger size, and frequently associated with thrombus.

• The status of the LAD and its graft significantly influences the selection process.( because lack of survival benefit of repeat surgery to treat non-LAD ischemia.)

Interventions within hours of C.A.B.G:

• urgent coronary angiography may reveal a compromised graft.

• Once a graft is thrombosed-------opening of the native vessel is preferable.

• if the native vessel is not a reasonable target------------- balloon interventions (thrombectomy device) on the graft are also effective if thrombus formation is not extensive.

• ? Intracoronary thrombolytic therapy-1/3rd requiring mediastinal drainage due to bleeding.

Native coronary interventions

• One year after C.A.B.G,– patients begin to develop new atherosclerotic

plaques in the graft conduits or – show atherosclerotic progression in the native

coronary arteries.

Approaches to native vessel sites in post-bypass patients

• Treatment of protected left main disease.• recanalization of old total occlusion or• native artery via venous or arterial grafts.

Intervention of the aorto-ostial lesion

• there is a question about need of prior debulking followed by stenting or stenting alone of the aorto-ostial lesion.

• In a study by Ahmed et al. for both groups of patients with or without prior debulking, the TLR rate after one year was similar at 19%.

• The technical concern during PCI of large and bulky aorto-ostial lesion is the antegrade and retrograde embolization.

• There is distal protective device for antegrade embolization but there is none for retrograde embolization

Saphenous vein graft interventions• 1-3yrafter surgery, patients begin to develop atherosclerotic

plaques in the SVG.• after 3 years, these plaques appear with increased frequency. • At the early stage, dilation of the distal anastomosis can be

accomplished with little morbidity and good long-term

patency (80–90%). • Dilation of the proximal and mid-segment of the vein graft

was highly successful at 90%, with a low rate of mortality (1%), Q-wave MI, and CABG(2%).

• The rate of non-Q-wave MI was 13%.

Intervention in degenerated saphenous vein grafts:

• The lesions that are bulky or associated with thrombus are considered to be high-risk.

• The complications include distal embolization, no-refl ow, abrupt closure, and perforation.

• So different approaches were devised because there is much to lose from the standpoint of distal embolization causing non-Q MI and increasing long-term mortality.

• In the case of perforation of SVG, usually there is contained perforation rather than cardiac tamponade due to the extrapericardial course of the grafts and extensive post-pericardiotomy fi brosis

Rheolytic thrombectomyRheolytic thrombectomy

Dissolution and removal of Dissolution and removal of clots from coronary and clots from coronary and peripheral arteries is achieved peripheral arteries is achieved by the creation of a flow-by the creation of a flow-mediated vacuum in the mediated vacuum in the vicinity of the treated lesion. vicinity of the treated lesion.

High speed injection of saline High speed injection of saline fluid into an aspiration catheter fluid into an aspiration catheter forms a low pressure zone at forms a low pressure zone at its orifice (the Bernoulli effect). its orifice (the Bernoulli effect).

Hypo tube

Water jets

Exhaust lumen

The pressure gradient between the thrombus The pressure gradient between the thrombus and the catheter tip draws clot particles into the and the catheter tip draws clot particles into the lumen of the device, where they are further lumen of the device, where they are further fragmented by the high speed saline jets and fragmented by the high speed saline jets and then aspirated. then aspirated.

The double lumen device allows both saline The double lumen device allows both saline injection and aspiration of particulate matter into injection and aspiration of particulate matter into its collection system.its collection system.

In the VeGAS 2 trial, the Angiojet In the VeGAS 2 trial, the Angiojet device was compared with device was compared with urokinase prior to percutaneous urokinase prior to percutaneous treatment of 346 patients with treatment of 346 patients with thrombus-rich lesions in native thrombus-rich lesions in native coronary arteries or SVG’s.coronary arteries or SVG’s.

In this high risk population, In this high risk population, procedural success and hospital procedural success and hospital course without a major adverse course without a major adverse cardiac event were achieved cardiac event were achieved with the Angiojet catheter in 86% with the Angiojet catheter in 86% of cases, significantly more of cases, significantly more frequently than with urokinase frequently than with urokinase (66%, P = 0.01)(66%, P = 0.01)

1.7%

15.0%13.9%

3.0%

33.1%30.8%

0%

10%

20%

30%

40%

Death MI MACE

Angiojet

Urokinase

3.3%0.6%3.3%

11.8%

3.0%

13.6%

0.0%

5.0%

10.0%

15.0%

20.0%

Any Surgical Repair Transfusion

Angiojet

Urokinase

Aspiration thrombectomyAspiration thrombectomy

The X-Sizer (EndicCOR The X-Sizer (EndicCOR Medical, Inc.,) is a Medical, Inc.,) is a thromboatherectomy catheter thromboatherectomy catheter of varying dimensions. of varying dimensions.

Rotation of a distal helical Rotation of a distal helical cutter results in thrombus cutter results in thrombus maceration and extraction into maceration and extraction into a distal vacuum collection a distal vacuum collection bottle. bottle.

Experience in several hundred Experience in several hundred pts has shown this catheter to pts has shown this catheter to be effective in debulking be effective in debulking thrombus and degenerating thrombus and degenerating SVG lesions . SVG lesions .

The X-TRACT trial The X-TRACT trial demonstrated that the demonstrated that the X-X-SizerSizer may be safely used as an  may be safely used as an adjunct to PCI of diseased adjunct to PCI of diseased SVGs and thrombus-laden SVGs and thrombus-laden native coronary arteries. native coronary arteries.

Less need for GP IIb/IIIa Less need for GP IIb/IIIa inhibitor bail-out in patients inhibitor bail-out in patients treated with the treated with the X-SizerX-Sizer, , suggesting a reduction in suggesting a reduction in periprocedural complications. periprocedural complications.

MACE rates at 30 days were MACE rates at 30 days were similar in both groupssimilar in both groups

There was a significantly lower There was a significantly lower incidence of large incidence of large postprocedural MI at 30-day postprocedural MI at 30-day follow-up among patients follow-up among patients treated with the treated with the X-SizerX-Sizer device.  device.

17.0 17.4

1.0

15.8

1.8 1.5

16.9

0.30

5

10

15

20

25

Cardiacdeath

MI TVR MACEInc

idenc

e (%)

X-SIZER Control

• In general, the X-Sizer system is more effective in removing thrombus and atheromatous debris .

• while the AngioJet system was effective only in the removal of fresh thrombus, and not the friable, grumous vein graft material or older organized thrombi

• ?Prevention of distal embolisation– Distal protection devices.– Proximaal protection devices.

SAFER Trial – Comparison of SAFER Trial – Comparison of PercuSurge to Routine Stenting in SVG’sPercuSurge to Routine Stenting in SVG’s

801 Patients Randomized801 Patients Randomized

30 Day MACE

Reduced 42%

P<0.001

Baim et al. Circulation 2002; 105: 1285.

Routine PercuSurge

%

0

20

16.5%

9.6%

The 800 patient multicenter randomized SAFER The 800 patient multicenter randomized SAFER trial demonstrated a 50% reduction in in-hospital trial demonstrated a 50% reduction in in-hospital adverse events with PercuSurge distal adverse events with PercuSurge distal protection during SVG stenting, when compared protection during SVG stenting, when compared to stenting without protectionto stenting without protection

Preliminary experiences with the PercuSurge Preliminary experiences with the PercuSurge in AMI patients undergoing percutaneous in AMI patients undergoing percutaneous intervention suggest that normal myocardial intervention suggest that normal myocardial blush may be achieved in more than 60%blush may be achieved in more than 60%

PercuSurge SystemPercuSurge System

AdvantagesAdvantages

Captures smaller Captures smaller particles and particles and “humoral” mediators“humoral” mediators

Frequently applicable Frequently applicable

DisadvantagesDisadvantages

Transient occlusionTransient occlusion

Long “parking” Long “parking” segmentsegment

Side branches Side branches unprotectedunprotected

Two operatorsTwo operators

Filter wireFilter wire

..

In Filter wire-type devices, An emboli entrapment net is In Filter wire-type devices, An emboli entrapment net is mounted on a 0.014" guidewire and expanded distally to mounted on a 0.014" guidewire and expanded distally to the lesion. the lesion.

Intervention is then performed over the guidewire.Intervention is then performed over the guidewire.

Filters do not block distal blood flow when first deployed Filters do not block distal blood flow when first deployed unlike occlusive devices.unlike occlusive devices.

Dislodged material is caught by the distal filter, which is Dislodged material is caught by the distal filter, which is then closed and retracted only at the end of the then closed and retracted only at the end of the procedure.procedure.

Fire Trial: Randomized BSC/EPI Fire Trial: Randomized BSC/EPI Filter vs. PercuSurge in SVGPCIFilter vs. PercuSurge in SVGPCI

650 patients in 65 sites650 patients in 65 sites

Conclusion: FW not inferior to GWConclusion: FW not inferior to GWStone et al. J Am Coll Cardiol 2003; 41: 43A

FWFW GWGW

TIMI 3 FlowTIMI 3 Flow 95.7%95.7% 97.7%97.7%

Device SuccessDevice Success 95.5%95.5% 97.2%97.2%

DeathDeath 0.9%0.9% 0.9%0.9%

MIMI 9.0%9.0% 10.0%10.0%

QMIQMI 0.9%0.9% 0.6%0.6%

30 day MACE30 day MACE 9.9%9.9% 11.6%11.6%

PROXIMAL OCCULUSION PROXIMAL OCCULUSION DEVICES DEVICES

These devices occlude flow into the These devices occlude flow into the vessel using a balloon on the tip of or just vessel using a balloon on the tip of or just the tip of catheter the tip of catheter

Two proximal occulusion catheters are in Two proximal occulusion catheters are in use:use:

Proxis catheterProxis catheter

Kerberos embolic protection systemKerberos embolic protection system

With inflow occlusion , With inflow occlusion , retrograde flow generated by retrograde flow generated by distal collaterals or infusion distal collaterals or infusion through a ”rinsing “ catheter through a ”rinsing “ catheter can propel any liberated debris can propel any liberated debris back into the lumen of the back into the lumen of the guiding catheter guiding catheter

These have potential These have potential advantage of providing advantage of providing embolic protection even before embolic protection even before the first wire crosses the the first wire crosses the lesion.lesion.

Proxis In VesselProxis In Vessel

Benefits to Proximal Benefits to Proximal ProtectionProtection

Nothing crosses the lesion prior to Nothing crosses the lesion prior to protectionprotection

Protection of main vessel Protection of main vessel andand side side branchesbranches

Captures large and small particlesCaptures large and small particles Can handle large embolic loadsCan handle large embolic loads

• Is there a role for 2b3a inhibitors in SVG interventions ?