The document discusses interventions for recurrent ischemia after coronary artery bypass grafting, describing the typical causes of early and late ischemia, techniques for intervening on saphenous vein grafts including thrombectomy and aspiration devices to remove thrombus, and the use of distal protection devices during stenting to prevent embolization. It compares rheolytic thrombectomy, aspiration thrombectomy, and various distal protection devices. The role of glycoprotein IIb/IIIa inhibitors during saphenous vein graft interventions is also discussed.

1. S.V.G. Interventions.
DR GOPI KRISHNA

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

11. Patients who experience recurrence of
ischemia after CABG
lesions in
– saphenous vein graft (SVG).
– native arteries.
– internal mammary.
– Radial.
– gastroepiploic graft.
– proximal subclavian artery.

12. 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)

13. 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

14. 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.

17. • 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.)

18. 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.

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

20. 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.

21. 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.

22. 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

23. 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%.

24. 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

28. Rheolytic thrombectomy
 Dissolution and removal of Hypo tube
clots from coronary and
peripheral arteries is achieved
by the creation of a flow-
mediated vacuum in the Water
vicinity of the treated lesion. jets
Exhaust lumen
 High speed injection of saline
fluid into an aspiration catheter
forms a low pressure zone at
its orifice (the Bernoulli effect).

29.  The pressure gradient between the thrombus
and the catheter tip draws clot particles into the
lumen of the device, where they are further
fragmented by the high speed saline jets and
then aspirated.
 The double lumen device allows both saline
injection and aspiration of particulate matter into
its collection system.

30.  In the VeGAS 2 trial, the 40%
Angiojet device was compared 30% 33.1%
with urokinase prior to Angiojet
30.8%
percutaneous treatment of 346 20%
Urokinase
patients with thrombus-rich
lesions in native coronary 13.9% 15.0%
10%
arteries or SVG’s. 1.7%
3.0%
0%
Death MI MACE
 In this high risk population, 20.0%
Angiojet
procedural success and Urokinase
hospital course without a major 15.0%
adverse cardiac event were 13.6%
achieved with the Angiojet 10.0%
11.8%
catheter in 86% of cases,
significantly more frequently 5.0%
than with urokinase (66%, P = 3.3%
0.01) 0.0%
3.3% 0.6% 3.0%
Any Surgical Repair Transfusion

31. Aspiration thrombectomy
 The X-Sizer (EndicCOR
Medical, Inc.,) is a
thromboatherectomy catheter
of varying dimensions.
 Rotation of a distal helical
cutter results in thrombus
maceration and extraction into
a distal vacuum collection
bottle.
 Experience in several hundred
pts has shown this catheter to
be effective in debulking
thrombus and degenerating
SVG lesions .

32.  The X-TRACT trial
demonstrated that the X- X-SIZER Control
Sizer may be safely used as an 25
adjunct to PCI of diseased
SVGs and thrombus-laden 20
native coronary arteries. 16.9 17.0 17.4
15.8
15
 Less need for GP IIb/IIIa
Incidence (%)
inhibitor bail-out in patients 10
treated with the X-Sizer,
suggesting a reduction in
periprocedural complications. 5
1.0 0.3 1.8 1.5
 MACE rates at 30 days were 0
similar in both groups Cardiac MI TVR MACE
death
 There was a significantly lower
incidence of large
postprocedural MI at 30-day
follow-up among patients
treated with the X-Sizer device.

33. • 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

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

37. SAFER Trial – Comparison of
PercuSurge to Routine Stenting in SVG’s
801 Patients Randomized
20 30 Day MACE
16.5%
Reduced 42%
P<0.001
9.6%
%
0
Routine PercuSurge
Baim et al. Circulation 2002; 105: 1285.

38.  The 800 patient multicenter randomized SAFER
trial demonstrated a 50% reduction in in-hospital
adverse events with PercuSurge distal
protection during SVG stenting, when compared
to stenting without protection
 Preliminary experiences with the PercuSurge
in AMI patients undergoing percutaneous
intervention suggest that normal myocardial
blush may be achieved in more than 60%

39. PercuSurge System
Advantages Disadvantages
 Captures smaller  Transient occlusion
particles and  Long “parking”
“humoral” mediators segment
 Frequently applicable  Side branches
unprotected
 Two operators

40. Filter wire
.

42.  In Filter wire-type devices, An emboli entrapment net is
mounted on a 0.014" guidewire and expanded distally to
the lesion.
 Intervention is then performed over the guidewire.
 Filters do not block distal blood flow when first deployed
unlike occlusive devices.
 Dislodged material is caught by the distal filter, which is
then closed and retracted only at the end of the
procedure.

43. Fire Trial: Randomized BSC/EPI
Filter vs. PercuSurge in SVGPCI
650 patients in 65 sites
FW GW
TIMI 3 Flow 95.7% 97.7%
Device Success 95.5% 97.2%
Death 0.9% 0.9%
MI 9.0% 10.0%
QMI 0.9% 0.6%
30 day MACE 9.9% 11.6%
Conclusion: FW not inferior to GW
Stone et al. J Am Coll Cardiol 2003; 41: 43A

49. PROXIMAL OCCULUSION
DEVICES
 These devices occlude flow into the
vessel using a balloon on the tip of or just
the tip of catheter
 Two proximal occulusion catheters are in
use:
Proxis catheter
Kerberos embolic protection system

50. Proxis In Vessel
 With inflow occlusion ,
retrograde flow generated by
distal collaterals or infusion
through a ”rinsing “ catheter
can propel any liberated debris
back into the lumen of the
guiding catheter
 These have potential
advantage of providing
embolic protection even before
the first wire crosses the
lesion.

52. Benefits to Proximal Protection
 Nothing crosses the lesion prior to
protection
 Protection of main vessel and side
branches
 Captures large and small particles
 Can handle large embolic loads

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