CTO PCI Manual Online cases: 38 , 92 , 98 , 112 , 125
PCI Manual Online cases: 18 , 21 , 40 , 44 , 57 , 68 , 72 , 81
Acute vessel closure is defined as (partial or complete) decrease in antegrade coronary flow that occurs during or immediately after percutaneous coronary intervention.
Fig. 25.1 outlines a step-by-step algorithm for approaching such lesions.
25.1
Maintain guidewire position
Acute vessel closure can lead to significant patient and operator stress, which may in turn lead to inadvertent removal of the previously delivered guidewire. Losing guidewire position can have catastrophic consequences, especially if acute vessel closure is due to a dissection, and should be avoided at all cost . Losing guidewire position can be the result of guide catheter manipulation, hence continuous attention to the guide catheter position is recommended throughout the procedure.
Remaining calm and maintaining true lumen guidewire position (if the guidewire was placed in the true lumen prior to the complication) is key for successfully managing acute vessel closure.
25.2
Determine the cause of acute vessel closure and treat accordingly
Treatment of acute vessel closure depends on the cause ( Table 25.1 ). The key differentiation is between dissection (that requires stenting) and distal embolization (that may actually worsen from stenting and requires physical removal of thrombus or debris and/or vasodilator administration).
| Mechanism | Risk factors | Diagnosis | Treatment |
|---|---|---|---|
| 1. Dissection |
| Angiography OCT, IVUS |
|
| 2. Thrombosis |
|
|
|
| 3.1. Embolization—thrombus |
|
|
|
| 3.2. Embolization—plaque |
|
|
|
| 3.3. Embolization—air |
|
|
|
| 4. Side branch occlusion after stenting |
|
|
|
| 5. Spasm |
| Angiography+response to vasodilators |
|
| 6. Pseudolesions | •Severe tortuosity | Angiography |
|
| 7. Equipment entrapment |
| Angiography |
|
| 8. Intramural hematoma | •SCAD, large lipid-rich plaque, use of cutting balloons | IVUS, OCT |
|
25.2.1
Dissection
In coronary dissection there is separation of the various layers of the coronary arterial wall. Angiographically, a dissection appears as a linear or spiral filling defect within the vessel lumen, although in severe cases complete vessel occlusion may occur ( Section 6.8.6 ).
The consequences of dissection depend on:
- •
the severity of coronary flow obstruction (none, partial, or complete cessation of coronary flow), and
- •
the location of the dissection (more proximal dissections, such as in the left main, can have more profound consequences as they cause a larger area of ischemia, potentially leading to arrhythmias and hemodynamic compromise).
Causes:
- •
Injection of contrast despite dampened pressure waveform ( Chapter 5 : Coronary and graft engagement, Section 5.6 ).
- •
Non-coaxial guide catheter position.
- •
Guidewire crossing attempts ( Chapter 8 : Wiring, Section 8.6 , Section 8.7 , Section 8.8 ).
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Lesion preparation (balloon angioplasty, atherectomy, laser, especially use of oversized balloons).
- •
Balloon rupture ( Fig. 25.2 ).
Figure 25.2
Dissection due to pinhole balloon rupture. An undilatable mid LAD lesion was ballooned with a 3.0×8 mm noncompliant balloon at 30 atm ( arrow , panel A). A pinhole balloon shaft rupture created a subintimal dissection ( arrows , panels C and D), that was treated with stenting and an excellent final result ( arrows , panel E).
Courtesy of Dr. Abdul Hakeem.
- •
Heavily calcified and tortuous lesions.
- •
Stenting ( Chapter 10 : Stenting, Sections 10.2.3 and 10.2.13).
- •
Spontaneous coronary artery dissection ( Chapter 22 : Other complex lesion types, Section 22.1 ).
- •
Aortic dissection: aortic dissection may involve the coronary ostia causing partial or complete occlusion.
Prevention:
- •
Do not inject contrast if there is dampened pressure waveform.
- •
Achieve coaxial catheter position.
- •
Avoid aggressive wiring strategies; avoid using polymer-jacketed guidewires as workhorse.
- •
Avoid use of oversized balloons and very high-pressure balloon inflations.
- •
Preparation of calcified lesions.
Treatment:
- •
Small, non-flow limiting dissections do not require treatment. OCT ( Chapter 13 : Coronary intravascular imaging) is very sensitive in identifying dissections (as compared with IVUS) . Proximal edge dissections after stenting most often do not require treatment, as the stent prevents forward propagation of the dissection .
- •
If wire position is maintained into the distal true lumen, stenting is performed.
- •
If there is no wire into the distal true lumen, various guidewires can be used in an attempt to enter into the distal true lumen (parallel wiring).
- •
IVUS can help confirm distal true lumen position. Injection of a collateralizing vessel, if available, can also help opacify the distal true lumen. Alternatively a microcatheter can be advanced distally and contrast injected, however, if the wire is subintimal, contrast injection will enlarge the subintimal space and make reentry into the distal true lumen more challenging. A safer strategy is to advance the microcatheter distally and then attempt to advance a workhorse guidewire. If the guidewire is in the true lumen it will reach the distal vessel without resistance. If the guidewire is in the subintimal space, significance resistance will be encountered when attempting to advance it.
- •
If wiring into the true lumen fails, CTO techniques (such as use of the Stingray balloon , retrograde crossing , or STAR [subintimal tracking and reentry]) can be used to achieve wire crossing into the distal true lumen.
- •
Avoid contrast injections; if they are absolutely needed they should be performed nonselectively with the catheter disengaged from the coronary ostium to avoid propagation of the dissection.
- •
Rapid stent delivery and deployment is needed, especially for proximal dissections, such as left main dissections .
- •
If a stent cannot be delivered due to significant tortuosity, calcification, or other reasons, balloon angioplasty or using a guide catheter extension may be needed first. Sometimes prolonged balloon angioplasty alone may be sufficient (although stenting is preferable, if feasible).
- •
If attempts to advance a guidewire into the distal true lumen fail, emergent surgery may be needed (e.g., left main dissections). Medical therapy may suffice in patients with small dissected vessels.
- •
If the cause of an ostial lesion is aortic dissection, emergency cardiac surgery is required with replacement of the aortic root.
25.2.1.1
Aorto-coronary dissection
CTO Manual Online case: 10 , 112 , 118 PCI Manual Online cases: 45 , 79
Aorto-coronary dissection is a rare complication which can occur with any PCI, but is more common with CTO PCI (especially retrograde procedures) (frequency was 0.8% to 1.8% in two contemporary series ) and most commonly occurs in the right coronary artery ( Fig. 25.3 ) . Dissection may be limited to the coronary sinus, but may extend to the proximal ascending aorta or even beyond the ascending aorta .
Causes ( Fig. 25.4 ) :
- •
Deep coronary engagement and utilization of aggressive guide catheters, such as 8 French Amplatz left catheters.
- •
Guide catheter pressure dampening.
- •
Forceful contrast injection, especially through “wedged” guide catheters with dampened pressure waveform.
- •
Predilation of the coronary ostium.
- •
Balloon rupture.
- •
Retrograde wire advancement into the subintimal and subaortic space during the reverse CART procedure.
- •
Antegrade attempts to recanalize a true aorto-ostial CTO.
- •
Aortic dissection extending into the coronary ostia.
- •
