Θεματική ενότητα: Stenting Μ. Ματσάγκας, MD, PhD, FEBVS Σάββατο 1 Φεβρουαρίου 2014

Stenting Acute Complications of Stent Placement Late Complications of Stent Placement

Acute Complications of Stent Placement Arterial dissection Arterial occlusion Arterial rupture Migration or embolization of the stent Embolization of atherosclerotic material

Arterial dissection If acute arterial dissection occurs in juxtaposition to a stent, an additional stent is placed in this location The lead point for arterial dissection associated with stent placement is usually within a centimeter of the end of the stent A stent is placed in this segment even if it is not clear exactly where the lead point of the dissection is located

Arterial dissection

Arterial occlusion The stented site may occlude as a result of arterial dissection or as a result of placement of a stent that is not fully expanded After stent placement, additional balloon dilatation is usually performed to ensure full expansion of the stent If the problem is not resolved, check outflow thoroughly, consider the use of covered-stent

Arterial rupture If the stent has been fully deployed, a balloon catheter is inserted and placed within the stent along the area where the rupture is thought to have occurred and the balloon is inflated A covered stent is placed in the same location Emergency operative repair is undertaken

Migration of the stent Migration of the stent may occur during deployment, usually because the size of the stent that was required was underestimated If the stent has migrated enough that the area of interest has not been adequately stented, another stent is placed in this location

Embolization of the stent Use a long sheath and a loop snare to pull or push into a favorable location to retrieve surgically (common femoral artery) to abandon (internal iliac, deep femoral, or tibial arteries)

Embolization of atherosclerotic material Distal embolization may occur as a result of instrumentation of a friable atherosclerotic lesion It is unusual for further embolization to occur after the entire lesion has been covered with stents

Late Complications of Stent Placement Intimal hyperplasia Recurrent stenosis Infection Stent damage

Intimal hyperplasia Recurrent stenosis Intimal hyperplasia can be treated with repeat balloon dilatation additional stents directional atherectomy surgery If recurrent stenosis occurs in juxtaposition to a stent, an overlapping stent is placed

Infection Infection of a stent is rare and is managed by excising the stent, usually along with the arterial segment Balloon-expandable stent requires surgical removal: if the stent is fully deployed, the artery probably requires reconstruction. An artery cannot be occluded with a clamp at the location of a stent. The ends of the stent are sharp Self-expanding stent requires surgical removal: the stent may be extracted by squeezing it, which narrows the whole stent

Stent damage Stents can be damaged by external forces Chronic repetitive shoulder motion with compression of a stented subclavian artery against the first rib leads to stent fracture Stents can also be crushed, especially the balloon- expandable stents, by: arterial clamps blood pressure cuffs motion at joints external blunt trauma

Bailout maneuvers for balloon-expandable stents Balloon with stent will not pass through the sheath: The sheath may have kinked Consider pulling the kinked part of the sheath back into a straighter segment of the artery and try again to pass the balloon and stent Pull out the balloon and stent with the sheath but leave the guidewire in place. Change the sheath and start again Predilate the lesion; use a larger sheath and stiffer wire Consider using a self-expanding stent for tortuous arteries

Bailout maneuvers for balloon-expandable stents Balloon with stent will not pass through the sheath

Bailout maneuvers for balloon-expandable stents Loose stent on the catheter shaft: Pull the balloon back into the stent using the tip of the sheath to pin the stent Pull the stent back into the sheath, if possible Use a partially inflated balloon to pull the stent and remove the sheath If the stent cannot be pulled back into the sheath, pin the back end of the stent with the tip of the sheath and deploy in a neutral location

Bailout maneuvers for balloon-expandable stents Loose stent on the catheter shaft

Bailout maneuvers for balloon-expandable stents Loose stent on the guidewire : Advance small balloon into the stent to flare the end and stabilize Deploy in a neutral location

Bailout maneuvers for balloon-expandable stents Balloon ruptures during deployment: Perform high-pressure, hand-powered balloon inflation with saline solution in an attempt to overwhelm the hole in the leaky balloon Advance the sheath to pin the stent so that it is not withdrawn with the balloon Rotate and remove the ruptured balloon Cross the stent with another balloon, and inflate

Bailout maneuvers for balloon-expandable stents Loose stent on the catheter shaft

Bailout maneuvers for balloon-expandable stents Stent tilts: Some balloon-expanding stents are too rigid for tortuous arteries. Self-expanding stents are often a better choice Place another stent to straighten the curve

Bailout maneuvers for balloon-expandable stents Stent tilts

Bailout maneuvers for self-expanding stents End of the stent is not fully expanded: The hoop strength of the self-expanding stent may not be adequate to compress the lesion Dilate the body of the stent to make sure it is properly seeded, and then dilate the ends

Bailout maneuvers for self-expanding stents End of the stent is not fully expanded

Bailout maneuvers for self-expanding stents Stent extends into undesired location: Dilate the stent to foreshorten it. This works well with a Wallstent Other types of self-expanding stents can sometimes be moved a very short distance by inflating a balloon and pulling gently on the catheter

Bailout maneuvers for self-expanding stents Stent extends into undesired location

Bailout maneuvers for self-expanding stents Stent location is inaccurate: The only way to avoid this is to deploy the end of the stent first that has the greatest precision requirement

Bailout maneuvers for self-expanding stents Stent location is inaccurate

Bailout maneuvers for self-expanding stents The end of the stent extends into the introducer sheath: The stent will not deploy If the tip of the sheath does not have a radiopaque marker, it may be difficult to visualize Pull the sheath back slightly while holding the stent delivery catheter in place to release the crimped stent

Bailout maneuvers for self-expanding stents The end of the stent extends into the introducer sheath

Bailout maneuvers for self-expanding stents Stent collapses in its midsection: Repeat angioplasty If that is unsuccessful, place a balloon-expandable stent inside the self-expanding stent

Bailout maneuvers for self-expanding stents Stent collapses in its midsection