I asked some of my experienced colleagues, how much time they inflate the balloon to deliver a stent? Most answers were spontaneous and unanimous “It’s hardly 10 seconds, few said maybe up to 15s.
Can prolonged balloon inflation time reduce the need for post dilatation and prevent mal-apposition?
We know high-pressure Inflation( up to 20 atmospheres ) was a big revelation in the science of PTCA more than two decades ago. (Antonio Colombo JACC 1995 ) He proposed and proved high-pressure inflation eliminated the need for routine anticoagulation following stenting as approximation was better. He also pioneered the concept of dual antiplatelet therapy (DAPT) in the PCI arena.
Similarly, prolonged balloon Inflation (30 to 60sec) could be another trendsetting tip to prevent malposition. It delivers more sustained pressure. Its believed the imparted centrifugal force and the inbuilt radial forces add up to the stent vessel wall Interface and prevent mal-apposition.
Is there a downside to high-pressure Inflation?
There must be few. Potential new Ischemic events and arrhythmia. In calcium laden plaques( spur) risk of perforation may be enhanced.
Final message
I don’t know why this concept never took off. Many of us still fear to inflate the stent balloon no longer than 10 to 20 seconds? Adhoc post dilatation with short NC balloon appears mandatory in areas of mal-apposition. Meanwhile, we also understand sustained (30-60s) high-pressure initial inflation could deliver the stent in a more synchronized and smooth fashion with a perfect metal/vessel wall interface. Further , prolonged balloon inflation times could make a routine (By the way who does routine ?) IVUS/OCT redundant.
What do the experts say? What does science say? There is one meta-analysis that clearly says the advantage of long inflation time. This issue becomes much more relevant as it could avoid post dilatation which all of us know can be tricky. In fact, every balloon dilatation should be technically counted as another PTCA procedure and adds up to net total risk.
Reference
1.M. Saad, M. Bavineni, B. F. Uretsky, and S. Vallurupalli, “Improved stent expansion with prolonged compared with short balloon inflation: a meta-analysis,” Catheterization and Cardiovascular Interventions, vol. 92, pp. 873–880, 2018. View at Google Scholar
Dr.S.Venkatesan MD 