Chronic Total Occlusions: Why, when and how?

Chronic Total Occlusions (CTO): TEN COMMANDMENTS DR.NILESH TAWADEJASLOK HOSPITAL AND RESEARCH CENTRE, MUMBAI

WHY IS IT BENEFICIAL TO OPEN A CTO?

Angina relief Improved L V function Better survival with successful PCI Avoidance of CABG Improved tolerance of a future ACS Similar risk to non CTO PCI Better procedural safety and success rate with experienced operators

CTO PCI will mostly benet patients who have angina refractory to optimal medical management and those with large ischemic burden

PATIENT SELECTIONWhen the CTO is the lone obstructive lesion in the coronary vasculature tree , there are three conditions which, when present, favor PCI.

The first condition is the presence of symptoms.

The second condition to consider is the presence of viable myocardium.

When the likelihood of success is moderate to high (>60%) If distal segment is not visible ANTEGRADELY OR RETROGRADE by collaterals is a serious contra-indication to attempt CTO

Predictors of success and failure in PCI of CTOFavorable Duration 15 mmMultivessel disease

5

BUT However, these classic unfavorable features may no longer constitute unsurpassable hurdles with the employment of the innovative technical approaches.Indeed, the absence of a visible distal vessel is the ONLY contraindication to a CTO attempt.

Case Selection, Angiographic Views, PharmacologyDo not attempt ADHOC and go with full preparedness .

Review the lesion from multiple views in orthogonal projections.

The use of simultaneous ipsilateral and contralateral injections is strongly recommended to define the occluded vessel/stump anatomy.

Angulations for Common Collaterals

ArteryCollateralPrimaryAngulationSecondary AngulationLAD-PDASeptal-septalRAO cranialRAO caudalLCX-RCAAV groove epicardialLAO cranialRAO caudalOM-DIAGONALEpicardialRAO caudalLAO cranialRCA-LADSeptal RAO OR AP cranialRAO caudal

PHARMACOLOGYSince no CTO procedure is considered emergent, appropriate pretreatment with dual anti-platelates (loading and maintance) should be ensured .

An activated clotting time above 180 seconds is adequate during typical antegrade wire manipulations, but additional heparin may be required for prolonged procedures

Particularly If a retrograde approach is followed THEN, a higher activated clotting time is necessary (above 250300 seconds).

PHARMACOLOGY

10

VASCULAR ACCESS

Guiding catheter selectionGuiding catheters that provide extra back-up support and coaxial alignment should be chosen

12

Guidewire selectionFalse passage entry into distal segment is very common , have low threshold for parallel wire. the vast majority of failures occur because an operator cannot cross the lesion. Wires designed for treating CTOs can be divided into two groups: polymer-coated (hydrophilic or lubricious) guide wires and non-coated coil guide wires; both groups also possess tapered and non-tapered tips. Operators should become familiar with all wire types, and select certain wires with which to become more comfortable,

Evolution of CTO-PCI Increasing success rates related to technique evolution 20042007 2010 2012

AFTER SUCCESSFUL WIRE CROSSINGAfter passing both the stiff guide wire into the distal lumen change it over to floppy tipped guide wire with the help of micro-catheter or OTW balloon to avoid perforation or dissection.

18

Crusade catheter for side branch access

Crusade For Side Branch Access

IPSILATERAL RETROGRADE

Ipsilateral retrograde

RETROGRADE TECHNIQUEDonor vessel should be normal if diseased significantly correct that first.Select septal connection with least tortuosityIf epicardial channel selected , be prepared for remote possibility of cardiac tamponade Avoid antegrade injection in reverse CART liberal use of IVUS

After successful dilation of the occlusion

When to STOP!

Wire or device perforation with pericardial effusion Hemodynamic instability Collateral vessel compromise Extensive dissection compromising distal runoff Contrast threshold (5 body weight/serum creatinine ) Radiation threshold Stage for second attempt Refer to more experienced operator CTO Procedural Considerations

In reviewing several previously attempted CTOs, it has learned anecdotal observation that a few months of dual antiplatelet therapy can facilitate thrombus resolution and new micro channels can develop after healing of the dissections left at the end of the original procedure that may ultimately facilitate the second attempt.

finally

Assess your expertise accurately Do not hesitate to take helpPatient's safety is utmost ----DO NO HARM Radiation dose Contrast dose Human fatigue

CONCLUSION

The woods are lovely, dark, and deep,But I have promises to keep,And miles to go before I sleep,And miles to go before I sleep-ROBERT FROST