how to reduce the coronary stent movement before deployment

1. Stabilization of Coronary Stent
movement before deploying
Dr.Nilesh Tawade
FNB

2. CASE
• 62 yr old lady
• Diabetic /HTN
• P/W NSTEMI
• ECHO – INFERIOR WALL HYPOKINESIA EF 45%
• CAG – LAD prox- 80% near the bifurcation with
D1 and tubular 70-80% lesion at proximal RCA
• PLAN – RADIAL ROUTE PTCA TO LAD & RCA

12. INTRODUCTION
• Accurate placement of intracoronary stents is necessary to
treat discrete stenotic lesions of coronary arteries during PCI
particularly in the treatment of ostial and bifurcation lesions.
• However, in some cases, the precise positioning of the stents is
prevented by excessive movement of the stent within the
artery due to myocardial contraction
• Inaccurate stent placement may result in incomplete target-
lesion coverage or may cover a previously uninvolved branch
vessel.
• In some cases, poor positioning of the stent may require a
second stent is needed to cover the entire target area.

13. METHODS TO REDUCE STENT
MOVEMENT
• There are several methods to reduce the cardiac-cycle
related movement of the stent delivery system,
• Holding breath.
• Deep guide-catheter engagement.
• Simultaneously wiring LCX and LAD. (anchor-wire technique)
• Placement of a parallel guide wire (buddy wire technique)
• Floating wire technique.
• Rapid right ventricular pacing.
• Rapid coronary wire pacing.
• Partial balloon inflation of the stent delivery system.
• If there is a reasonably sized side branch proximal to the
lesion, a balloon (anchor-balloon technique) can be inserted
deeply into this branch to fix the stent position .(too invasive)

14. VARIOUS METHODS & LIMITATIONS
• Deep guide-catheter engagement ; EASY WAY ; BUT -may
cause pressure damping or coronary vessel injury, and the
catheter tip may extend into the segment requiring stent
coverage.
• The partial inflation of a stent balloon at low pressure to
create friction between the stent delivery system and the
vessel wall can reduce the stent motion during cardiac cycle,
but precise stent placement may still remain challenging due
to uncertainty of the stent expansion.
• Moreover, partial stent deployment may increase the risk of
stent loss or deformation within the coronary artery.

15. RV PACING
• Right ventricular pacing by catheters is not
always without complications.
• It can cause ventricular perforation, cardiac
tamponade, and vascular access-site
complications.
• Other disadvantages of this technique are the
longer procedure time and greater
consumption of material resources.

16. Floating-Wire Technique
• After the stent delivery system is placed around the
target lesion, the catheter was carefully withdrawn
to disengage the tip.
• Next, the second wire was advanced into the aortic
root, where it remained floating.
• The catheter was then advanced over the vessel
wire, with constant forward pressure against the
shaft of the floating wire to maintain alignment
adjacent to the ostium.

21. In the present study, this technique was mainly
applied in PCI of the right coronary artery.
• In right coronary artery PCI via the radial access route, the Judkins
right catheter is the most frequently used guide catheter.
• However, this catheter cannot contact the contralateral aortic wall
at all and its back-up force is much weaker when compared with
the guiding catheter for the left coronary artery, so the stability of
the entire device system is poor and the stent delivery system is
more prone to movement.
• When difficulty is encountered in stent positioning during left
coronary artery PCI, some adjunctive techniques, such as the
anchor-wire or anchor-balloon technique, can be used to reduce
stent movement.
• However, the above adjunctive techniques are less suitable to be
used in facilitating exact stent placement in the right coronary
artery because there is no reasonable side branch
• Thus, the floating-wire technique may be more suitable for RCA
lesions

22. Advantages
• There are many advantages of this technique, such
as simplicity of operation, short learning curve, short
procedure time, and low cost.
• Moreover, the floating wire can prevent deep
engagement of the guide catheter, thus avoiding
damage to the coronary artery ostium and
limitations in coronary flow, and thereby may be
especially suitable for cases of aorto-ostial stenosis.

26. METHODS
• Tachycardia was induced in all cases while pacing at
100 and 150 beats/min. The stent was then relocated
in the desired position
• Using the same principles when permanent
pacemakers are functioning in Unipolar mode.
• The guidewire therefore acts as a negative electrode
or cathode (the role performed by the distal end of the
pacemaker electrode) and the skin acts as the positive
electrode or anode (the role performed by the
pacemaker casing).

28. Discussion
• Tachycardia was induced safely and effectively and, using a
temporary pacemaker, achieves the same results as right
ventricular pacing, thus avoiding the need for central
venous catheterization.
• Symptomatic electrical stimulation of the diaphragm
occurred in 11% of cases and electrical sensation at the
puncture site in 7% of cases but it was well tolerated in the
study
• In contrast to slow stimulation (100 beats/min), rapid
stimulation (150 beats/min) was effective in 96% of cases
(P<.001) and stent deployment was considered successful
in all cases
• Coronary spasm can be the issue. ???

29. Szabo technique
• The technique was first described by Szabo et al in 2005 and
involves a second guide wire placed in the aorta (or branch vessel
for a non aorto-ostial lesion) to anchor the stent.
• The stent is prepared by a low pressure inflation (1-2 atm) with the
protective sleeve left in place while exposing the proximal struts.
The remainder of the stent is compressed with the sleeve.
• The wire is passed through the proximal strut of the stent followed
by crimping of the “lifted” strut; however, not to the degree that
the anchor wire is not mobile.
• The stent then travels over the primary guide wire and the anchor
wire, which stops forward motion of the stent at the ostium
• The stent is then deployed at low or nominal pressure, followed by
removal of the anchor wire. The stent balloon can then be
reinflated or another balloon can be used to post dilate.

33. Limitations
• Caution must be used when applying this technique.
Intravascular ultrasound follow-up has demonstrated stent
protrusion and distortion, which may be more a concern in
non aorto-ostial lesions.
• In addition, there is the potential for stent dislodgment as a
result of stent manipulation
• While the Szabo technique is not without limitations, it seems
to provide complete ostial coverage for aorto-ostial lesions

34. BREAKFAST TIME