Tips & Tricks for Aorto-ostial Coronary Lesions | SCAI

Huu Tam Truong, MD, FSCAI; Kapildeo Lotun, MD, FSCAI; Hoang Thai, MD, FSCAI

Aorto-ostial coronary interventions present special technical challenges to interventionalists and are associated with geographic miss rates of up to 54 percent and a threefold increase in target lesion revascularization1

The objective is complete ostial stent coverage without excessive stent protrusion into the aorta, hindering future vessel cannulation. Challenges to precise stent deployment include pressure dampening, difficulty in delineating the true ostium angiographically, a very small landing zone, and respiratory and cardiac motions.

In this Tip of the Month, we focus on tips to overcome these challenges and optimize the outcomes of aorto-ostial interventions.

  1. Dealing with pressure dampening and delineating the true ostium
    a) Use a "nonaggressive" guide such as a JR4 to avoid deep intubation of the vessel.
    b) Use the “floating wire” technique (Video 1). Place one guidewire in the target vessel and a second guidewire in the aorta. The second wire will demarcate the true ostium and prevents the guiding catheter from intubating the vessel deeply. An alternative would be to use the dedicated device, Ostial ProTM (Merit Medical, South Jordan, UT)2.
     
  2. "Nailing" the ostium (minimizing distal geographic miss)
    a) Identifying two best possible fluoroscopic projections which identify the ostium is important. Steep LAO projection (RCA), LAO caudal & AP Cranial (Left main) are usually the best views.
    b) Know where the stent edge is relative to the radiopaque markers. Most currently available drug-eluting stent platforms have the stent just inside of the radiopaque markers, except for the XienceTM platform (Abbott Vascular, Abbott Park, IL), which crimps the stent at the center of the radiopaque marker. If there is difficulty localizing the stent edge, collimation followed by a high frame rate cine or stent boost will enhance visualization.
    c) Utilizing the Szabo technique can minimize distal geographic miss3, 4. This technique is performed by loading the stent on the target vessel wire and threading a second anchor wire (positioned in the aorta) through the most proximal stent strut (Figure 1). Once the stent is advanced to the lesion, the anchor wire will prevent the stent from migrating too distally past the ostium, and the stent is deployed at a low pressure. The anchor wire is withdrawn, and high-pressure inflation is performed to fully deploy the stent. Several observational studies have demonstrated success with this strategy, although stent deformation and dislodgement have been reported3, 4, 5.
    d) If there is difficulty positioning the balloon/stent proximally due to “flush” engagement of the guide (risking incomplete coverage), the balloon/stent may be deployed at a low pressure (6–8 atm) 1–2 mm inside the guide, ensuring the lesion is covered. The resistance from the stenosis will anchor the balloon/stent in place, and the remaining balloon/stent can be unsheathed from the guide followed by full deployment at a high pressure (Videos 2 and 3).
     
  3. Dealing with motion during stent placement placement (more common with an ostial RCA lesion and transradial approach)
    a) Respiratory motion can be resolved by having the patient hold his/her breath.
    b) Excessive cardiac motion for the RCA can be managed by administering 50–100 mcg of intracoronary adenosine, which results in a few seconds of asystole, allowing time for precise stent positioning.
    c) Avoid very short (8mm) stent as much as possible, to prevent stent loss during deployment.
     
  4. Performing Intravascular Ultrasound (IVUS)
    a) Pre-stenting IVUS can identify lesions that may need more aggressive preparation, such as a scoring balloon or rotational atherectomy, and aid with accurate stent sizing.
    b) Post-stenting IVUS can identify incomplete stent coverage, under-expansion, or excessive stent struts in the aorta. This practice often prompts further interventions to optimize results (such as post-dilation or placement of an additional stent) and has been associated with a lower risk of major adverse cardiac events 6.
     
  5. Flaring the ostium
    a) Post-dilation with a larger balloon, protruding into the aorta, will improve stent expansion and flare the aortic portion of the stent. This maneuver can be performed using the stent balloon as well.
    b) The FlashTM Ostial system (Ostial Corporation, Sunnyvale, CA) is a dedicated flaring device comprising of a high-pressure, coronary-size balloon and a larger low-pressure anchoring balloon (can expand up to 14 mm)7. This flares the stent struts which protrude 1-2 mm from the ostium and allows easier engagement of the ostium for future angiography and interventions.  (Video 4).

Figure 1: Illustration of the Szabo technique

 

Video 1:  Floating wire technique
Video 2: Balloon deployed partially in the guide at low pressure
Video 3: Balloon fully deployed after unsheathed from the guide
Video 4: Flaring the ostium with the FlashTM Ostial system

Summary:

Aorto-ostial lesions are challenging and geographic misses are common requiring meticulous techniques for success.  In this Tip of the Month, we have reviewed the different strategies that the interventionalist can employ in their daily practice to optimize outcomes.

 

References:

  1. Dishmon DA, Elhaddi A, Packard K, et al. High incidence of inaccurate stent placement in the treatment of coronary aorta-istial disease. J Invasive Cardiol. 2011;23(8):322–326.
  2. Fischell TA, Malhotra S, Khan S. A new ostial stent positioning system (Ostial Pro) for the accurate placement of stents to treat aorto-ostial lesions. Catheter Cardiovasc Interv. 2008 Feb 15;71(3):353–7.
  3. Szabo S, Abramowitz B, Vaitkus PT. New technique for aorto-ostial stent placement [Abstr]. Am J Cardiol 2005;96:212H.
  4. Kern MJ, Ouellette D, Frianeza T. A new technique to anchor stents for exact placement in ostial stenoses: The stent tail wire or Szabo technique. Catheter Cardiovasc Interv 2006;68:901–906.
  5. Gutiérrez-Chico JL, Villanueva-Benito I, Villanueva-Montoto L, Vázquez-Fernández S, Kleinecke C, Gielen S, Iñiguez-Romo A. Szabo technique versus conventional angiographic placement in bifurcations 010-001 of Medina and in aorto-ostial stenting: angiographic and procedural results. EuroIntervention. 2010 Feb;5(7):801–8.
  6. Patel Y, Depta JP, Patel JS, Masrani SK, Novak E, Zajarias A, Kurz HI, Lasala JM, Bach RG, Singh J. Impact of intravascular ultrasound on the long-term clinical outcomes in the treatment of coronary ostial lesions. Catheter Cardiovasc Interv. 2016 Feb 1;87(2):232–40.
  7. Nguyen-Trong PJ, Martinez Parachini JR, Resendes E, Karatasakis A, Danek BA, Alame A, Makke LB, Ayers CR, Roesle M, Rangan B, Banerjee S, Brilakis ES. Procedural outcomes with use of the flash ostial system in aorto-coronary ostial lesions. Catheter Cardiovasc Interv. 2016 Dec;88(7):1067–1074.

Related QI Tips

Other evidence-based methods and tools you can use to improve quality of care and outcomes for patients. 

QI Tips

Safe Femoral Access: Tips & Tricks

Transfemoral access is often required while using large-bore catheters in high-risk patients, and sometimes in urgent or emergent s...