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Posts Tagged ‘bifurcation pci’

Bifurcation PCI is a modern-day Cardiologist’s fascinating professional adventure within coronary arteries. Of course, one of their Intentions is to do good for the patient. Bifurcation lesions (BFL) are a special subset of lesions, that looks challenging, more because of the potential biological aftermath following the delicate construction of a grade separator at a critical site. Mind you, it’s done within a live flowing artery and subsequently needs lifelong maintenance.

Strategies for BFL

  1. Strictly committed* single stent strategy (Irrespective of what may come, LCX or LAD  pinching let me take care . Don’t worry strategy *May sound dangerous, but still, it doesn’t make other strategies less ominous) 
  2. Provisional single stent strategy with elective cross-over for truly poor result /cosmetic/peer satisfaction  purpose
  3. Provisional single stent with bail-out cross-over. Often happen as an emergency  (Not all techniques are amenable for this)
  4. Elective planned two stents (Still, flexible  to revert to single stent if the situation allows)
  5. Elective, strictly committed, prefixed  two-stent strategy  (No going back strategy/ Not really a professional PCI )
  6. Always remember, SYNTAX or no SYNTAX CABG is the safe & best bet for many severely symptomatic patients, with complex as well as non-complex BFL lesions esp in diabetic patients.

Wait, there are two more.

7. Please note, there is one benign strategy, that is always available, but hiding deep in the interventional cardiologist’s sub(non)conscious minds. It is a zero radiation, zero contrast, and almost zero cost strategy. Yes, It is “No stent strategy’ also called exclusive medical management, currently referred to as OMT/GDMT. In our analysis of symptom- lesions significance at least 30% of BFL are eligible for exclusive medical management.(FFR & IFRs ? Less we say about it, is better!) 

8. One more option for those patients (&cardiologists) who wants to travel the middle path is POBA or a Glorified POBA ie DEB  (Ref  Corballis NH,. PLoS One. 2021)

Whatever the treatment, bifurcation PCI  cannot be taken lightly. One exclusive club is debating this topic in Europe every year (EBC) for the past 10 years. Currently, Double kiss and crush (DK crush) is considered superior to others. Mini crush and Culotte are good alternatives in specific circumstances (Definition 2, NORDIC, BBC 2)

Something about DK crush (Shao-Liang Chen Nanjing, China first modified mini crush to DK crush)

Best video resource for DK crush 

 

In DK crush every step appears to be double. Apart from the double stent, it is a double wire cross, double crush, double kiss, and double POT (or even more). All must happen in a specific sequence. One may add double Imaging (Pre and Post PCI IVUS or OCT) to the list.  Finally and funnily not to miss the realistic possibility of double complications over the provisional strategy.

I am not sure which of the 10 steps in DK crush is most important. When we go through the physics of  BFL intervention it appears, that proper crushing and kissing may be the key to success. Though kissing is an integral part of any two stent strategies, in DK crush it happens in a unique interface between balloons /balloons with a stent and finally between two stents. In fact 

The physics of bifurcation kissing includes balloon hugging diameter, area, and pressure. Added to that is the intervening metal layer.

Can’t take the kissing in a casual manner. The Morino & Mitsuda model tells us more about the physics of kissing. In BFL interventions, kissing can happen with various layers that include one layer of the balloon with a crushed and non-crushed stent, carina. While we are mastering the techniques, we must realize, Kissing is aimed at stabilizing the carinal basement, still, there is a distinct possibility, that what may appear as innocuous kissing may undo all the good work we have done in previous steps. I guess, no harm in missing the final kissing if everything is ok in OCT.

Dr. Anonio Colombo’s take on kissing 

 

Final message

So, we have both simple and complex modalities for BFL. Evidence and experience reveal that 90 -95 % of patients with BFL would be eligible for the easy path. In one sense, we are indeed wasting our energy and resources in tackling this negligible CAD burden located at the summit of the global CAD pyramid with a gigantic base. However, we can feel scientifically happy, that we have gained considerable expertise in tackling complex lesions with multiple stent strategies in recent times. Still, we are far away from a true vision, of what really might follow such a niche & expertise-intensive procedure.

Let us hope, that modern metallurgy in combination with physics & hydrology would ultimately beat Biology.

Reference 

1.Dr Colomo article (For personal use only)

2..Morino Y, Yamamoto H, Mitsudo K, . Functional formula to determine adequate balloon diameter of simultaneous kissing balloon technique for treatment of bifurcated coronary lesions: clinical validation by volumetric intravascular ultrasound analysis. Circ J. 2008 Jun;72(6):886-92. doi: 10.1253/circj.72.886. PMID: 18503211.

Postamble

Does evidence create expertise?

Looking at the whole issue of complex PCI philosophically, no technique may really be superior based on accrued evidence. In fact, when expertise becomes the key determinant, the evidence goes to the background. It is really surprising we are too much dependent on hasty and often biased evidence to ratify our expertise, technique, or hardware. I know, one of my colleagues can cross any lesion with one or 2 wires.

To insist, that a particular technique must be followed may not be academically correct always. It is similar to telling a coach driver in advance when to apply a brake or accelerator when he is negotiating multiple hairpin bends in hilly terrain on a rainy day, based on clinical trials done with different drivers on different routes. Ultimately, the outcome is decided by the expertise of the driver, the condition of the vehicle, the road, and not least, the destiny of the passenger.

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bifurcation angle

  • At any branch point three angles are possible .True bifurcation angle is formed between LAD and LCX .
  • The angle between LM and LAD or LM and LCX can also be important in specific situations ,especially when we encounter short left mains and Medina 1,1,0 lesions .
  • Major bifurcation angle can  occur in mid  segments  as well ,  between LAD / major Diagonal  , LCX and OM.
  • Logic would tell us the  left main  bifurcation  angle is relatively fixed by the anatomical AV and IV grooves. Still early course of LAD and LCX can be out of grooves.
  • Further ,the bifurcation angle is imparted some amount of dynamism by cardiac cycle . It can vary between 80 -120 degrees (LAD/LCX).
  • Most importantly various  angiographic views can alter the true angle (by illusion ) in dramatic fashion . RAO caudal view appear ideal to measure it. (LAO caudal make every bifurcation angle obtuse !)
  • Acute angled bifurcations are prone for stent related mechanical issues both during deployment and in the long term outcome . (When two stent technique is used) This is because ,  acute  angled bifurcations has a tendency to drift the carina , and  encroach  the lumen  which can create new  turbulence . Of course final kissing balloon is expected to reduce this hemodynamic side effect at least on paper !

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