Treatment of distal anastomotic lesions
| Treatment of distal anastomotic lesions |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
Associate Editors-In-Chief: David M. Leder, M.D., Brian C. Bigelow, M.D.
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Background
Anastomotic lesions are the result of fibrosis and intimal hyperplasia, as opposed to thrombus burden as seen in the body of saphenous vein grafts. Anastomotic lesions require specific considerations, including:
- Potential differences in the diameter of the graft and native vessel.
- Tortuosity of (internal mammary artery) IMA grafts.
- Difficulty delivering devices due to distal location.
- Extreme angulation of the lesion.
Treatment Choices
Balloon angioplasty (PTCA)
PTCA is the simplest approach for treating distal anastomotic lesions. It also has the greatest chance of overcoming the limitations listed above.
Stenting
Stenting distal anastomotic lesions, particularly with drug eluting stents, reduces the risk of restenosis. However, proper placement and sizing of the stent may be challenging due to differences in the diameter of the graft and the native vessel. Furthermore, stenting across the anastomotic lesion may limit retrograde access of the native vessel proximal to the anastomosis.
Rotational Atherectomy
Rotational atherectomy may facilitate balloon expansion, but it may also be difficult to deliver in tortuous IMA grafts. Additionally, it is important to note that rotational atherectomy is contraindicated in thrombotic or degenerated vein grafts.
Transluminal Extraction Catheter (TEC)
This method is rarely used for anastomotic lesions because anastomotic lesions are not usually thrombotic and diffusely degenerated. When compared with PTCA and stenting, transluminal extraction catheters are associated with increased difficulty in delivering the device, as well as higher risks of dissection and possibly distal embolization.
Excimer Laser Coronary Angioplasty (ELCA)
ELCA is associated with a high initial success rate for the treatment of distal anastomotic lesions, but it also has a high rate of restenosis.
PCI Techniques
For lesions in nontortuous grafts with little difference between the SVG and native vessel diameters, stenting may be preferred due to its lower rate of target lesion revascularization.
In cases where the stent delivery may be difficult, PTCA with provisional stenting should be considered. The use of a buddy wire or second wire to straighten out the anastomotic junction may also be useful in such cases.
To effectively reach distal lesions, shorter guiding catheters or PTCA balloon catheters with long shafts may prove beneficial. Additionally, small catheters with side holes should be chosen for IMA PCI to avoid catheter damping, vasospasm, and injury to the IMA ostium.
Soft guidewires and/or hydrophilic wires for PCI of tortuous IMAs should be considered, as this helps avoid pleating and allows for the delivery of equipment.
Anticipated Outcomes
When distal anastomotic lesions are properly treated, angiographic success (as defined by normal flow (e.g. TIMI 3) and stenosis <50%) with resolution of ischemia without adverse cardiac events can be anticipated.
Other Concerns
Although rare, the rupture of distal anastomotic lesions is a concern, particularly if the CABG was recently performed.