Session 4: Technical Strategies - IVUS evaluation of dissections and healing – Yoshihisa Shimada

Current Situation of DCB in Japan

Growing Awareness and Usage

• The awareness of Drug-Coated Balloons (DCB) is increasing in Japan since its introduction in 2014.

• Current usage among Japanese fusions is reported to be over 20%, approaching 30%.

Challenges with Main Vessels

• Despite the seemingly high percentage, most DCB cases involve instant recinosis, small vessels, and side branches; main vessels account for only about 20% of all DCB cases.

• The low usage in main vessels is attributed to difficulties in lesion preparation.

Case Studies Demonstrating DCB Effectiveness

Case Examples

• A case involving the RCA showed that after cutting balloon angioplasty followed by DCB application, the follow-up indicated complete healing.

• Another case with a heavily calcified LED required rotablation before applying two long DCBs, resulting in beautiful healing without needing a stent.

STEMI Patient Insights

• In an ACS STEMI patient case, despite initial concerns requiring a stent due to spiral dissection, follow-up revealed complete healing without it.

Predictability of Healing with DCB

Basic Rules for Predicting Outcomes

• The speaker asserts that healing outcomes can be predictable if certain basic rules are understood regarding DCB angioplasty.

Rule One: Healing of Vascular Injury

• Any vascular injury will eventually heal; this was demonstrated through various imaging techniques showing significant recovery post-procedure.

Rule Two: Regression of Intimal Flap

• Intimal flaps tend to regress over time and disappear; examples were provided where initial observations showed flaps that later completely resolved at follow-up imaging.

Rule Three: Action on Vascular Wall

• Paclitaxel acts on the vascular wall rather than directly on plaque; this principle was illustrated through multiple cases demonstrating successful outcomes following treatment with DCB.

Practical Exercises and Predictions

Application of Rules in Practice

• Practical exercises were introduced to apply the three rules learned about predicting outcomes from angiographic images post-treatment using cutting balloons and DCB procedures.

Vascular Expansion and Drug Effects

Understanding Vascular Expansion Dynamics

• The speaker anticipated that the flap would disappear, leading to vessel expansion; however, the actual outcome was exaggerated vessel expansion due to potentially thin walls and strong drug action.

• It is noted from experience that vascular expansions typically stabilize within three to six months, indicating a benign form of aneurysmal remodeling rather than a severe complication.

Treatment Techniques and Observations

• A cutting balloon was applied across an extensive lesion, but only specific segments received drug-coated balloon (DCB) treatment due to budget constraints.

• Dissection was observed in areas not covered by DCB, raising questions about follow-up strategies for these complex cases.

Mechanisms of Restenosis

• The mechanism behind restenosis involves shrinkage of vasculature; this explains why certain areas were not treated with DCB and highlights the importance of understanding late management exaggeration.