What is the DK crush technique in interventional cardiology?

DK Crush Technique in Interventional Cardiology

The Double-Kissing (DK) crush technique is superior to other bifurcation stenting strategies for complex coronary bifurcation lesions, particularly for left main distal bifurcation disease, with significantly lower rates of major adverse cardiac events and target lesion failure. 1, 2, 3

What is the DK Crush Technique?

The DK crush technique is an advanced two-stent strategy for treating coronary bifurcation lesions, particularly when dealing with complex anatomies involving large side branches. It consists of the following sequential steps:

• Stenting the side branch (SB) first 4
• Balloon crush of the side branch stent against the main vessel (MV) wall 4
• First kissing balloon inflation (the first "K" in DK crush) 4
• Stenting the main vessel 4
• Final kissing balloon inflation (the second "K") 4

When to Use DK Crush

The DK crush technique is particularly indicated in the following scenarios:

• Complex bifurcation morphology involving a large side branch where the risk of side-branch occlusion is high 5
• Situations where the likelihood of successful side-branch reaccess is low 5
• Distal left main coronary artery bifurcation lesions 3
• True bifurcation lesions (Medina 1 or 0,1 classification) 3

Evidence Supporting DK Crush

Recent high-quality evidence strongly supports the use of DK crush in complex bifurcation lesions:

• Network meta-analyses have demonstrated that DK crush is superior to other bifurcation techniques in reducing device-oriented clinical events with a relative risk of 0.62 compared to provisional stenting 1
• The DKCRUSH-V randomized trial showed that in true distal left main bifurcation lesions, DK crush resulted in significantly lower rates of target lesion failure at 1 year compared to provisional stenting (5.0% vs 10.7%) 3
• DK crush also demonstrated lower rates of target vessel myocardial infarction (0.4% vs 2.9%) and definite or probable stent thrombosis (0.4% vs 3.3%) compared to provisional stenting 3

Technical Considerations for Optimal Results

To achieve optimal results with the DK crush technique, several technical aspects are critical:

• Careful rewiring from the proximal cell of the main vessel stent to ensure the wire is in the true lumen of the side branch stent 4
• Use of balloon anchoring from the main vessel 4
• Alternative inflation and kissing inflation using adequately sized non-compliant balloons at high pressure 4
• Implementation of the proximal optimization technique (POT) to improve both angiographic and clinical outcomes 4
• Intravascular ultrasound (IVUS) guidance is reasonable for assessment of complex bifurcation lesions and optimization of stent deployment 5

DK Crush vs. Other Bifurcation Techniques

When compared to other bifurcation stenting techniques:

• DK crush has been shown to be superior to provisional stenting, culotte, T-stenting, and other techniques in reducing major adverse cardiovascular events 2
• In rank probability analysis, DK crush ranked as the most effective treatment for MACE (100%), myocardial infarction (75%), stent thrombosis (83%), and target lesion revascularization (100%) 2
• For complex bifurcation lesions defined by DEFINITION criteria, DK crush was notably more efficacious than provisional, culotte, and T-stenting techniques 2

Modifications and Refinements

Recent refinements to the DK crush technique include:

• DK nanocrush: A modification that aims to minimize the amount of metal layers at the bifurcation while maintaining complete lesion coverage 6
• This technique positions the side branch stent with minimal protrusion into the main branch and creates a minimal neocarina 6
• Computational fluid dynamics analysis has shown that DK nanocrush results in minimally disturbed blood flow 6

Pitfalls and Caveats

Despite its advantages, the DK crush technique has some important considerations:

• It is technically more demanding than provisional stenting and requires expertise in complex PCI 4
• Proper stratification of bifurcation lesions is recommended before deciding on the stenting strategy 4
• Final kissing balloon inflation is mandatory after elective double stenting to optimize outcomes 5
• In patients with low-risk bifurcation lesions (minimal or moderate ostial side-branch disease of focal length), provisional stenting may still yield similar clinical outcomes with lower incidence of periprocedural biomarker elevation 5

Conclusion

The DK crush technique represents an important advancement in the treatment of complex coronary bifurcation lesions, particularly for distal left main disease. When performed with proper technique and in appropriate lesions, it offers superior clinical outcomes compared to other bifurcation stenting strategies.