“SIMPLE” CTO
- Chronic total occlusion is a different ball game compared to non-total occlusive disease
- There are a few key points to note when approaching a CTO
- Adequate angulation of the X-ray tube to obtain clear vessel path is essential
- Where there are overlapping of vessels on the 2D pictures the overlapped area must be carefully differentiated
- The following case illustrates this principle
This shows the LAD lesion in the cranial view
1 Base AP cran
This is the RAO cranial view
2 BASE RAO cran
This is the caudal view
3 Base AP caud
The crux of the matter
- Where is the entrance to the LAD?
- The operator in this case selected the LAO cranial view and spider view
- He then puts in 2 wires
- Do you agree?
LAO cranial view
4 LAO cran1st try
Spider view
5 Wrong entrance
After a while he changed position
6 Potentially correct but direction is wrong
From the AP cranial view
7 Wrong direction
Finally he put in 3 wires to try
Is this correct?
- One of the wires was a Conquest Pro 12
- Do you agree?
- After 300ml of contrast the procedure was abandoned
8 3 wires
Let us look at the angiogram again
On 1st look, the connection is apparently simple
What about the caudal view?
Where is the correct entrance?
Actually the wire has entered the Ramus in the 1st attempt
The 1st branch coming off the left main is the LAD. The 2nd is Ramus
On one of the attempts, the wire was actually correct
But the operator could not be certain on the AP cranial view
On the 2nd attempt/span>
- I selected XT-R wire in Corsair to start the procedure
- The entrance to LAD was an acute angle
- Therefore I put a secondary bend on the XT-R wire
- The CTO portion was a bit calcified
- I changed to XT-A to crossed the calcified portion
9 Select correct entrance
This angiogram with the wire in LAD explains why the LAD is confused with the Ramus
10 Accurate wiring
These 2 still shows the correct and incorrect path
The confusion arises due to overlapping vessels
After crossing the lesion a 1.5 x 15 balloon was used to dilate the vessel
11 After 15 balloon
This spider view shows the wire in the LAD and the Ramus to its right
12 the entrance from spider
After stenting with a 3.5mm stent, the LAD is now much bigger than the Ramus
15 Final RAO cran
It seems impossible now to confuse the ramus with the LAD
16 Final spider
Finally we can see the paths of both the ramus and LAD
17 Final AP caud
CONCLUSION
- Fortunately no perforation occurred in the 1st attempt when a stiff wire was used to attempt to penetrate the vessel
- The second attempt took barely an hour to complete including IVUS examination
- This is because the ostium of the LAD was correctly identified and appropriate wire selected
- Understanding anatomy is paramount for successful CTO intervention
- Even in “simple” CTO’s such as this case