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


  • 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