A theoretical model using mechanical principles to quantify the physical principles of balloon dilatation.

Rationale And Objectives: Balloon dilatation is a mechanical form of controlled injury used to alleviate vascular stenoses. Several factors influence successful angioplasty. Few mechanical models exist to illustrate the physical principles of balloon dilatation.

Methods: We used mechanical analysis of membrane stresses, along with Laplace's law, to determine a relation between balloon inflation and dilating pressures exerted by balloons in stenoses of varying severity, length, and eccentricity. The balloons were assumed to be perfectly inelastic and flexible. We also examined the resultant stresses in the lesion wall of concentric and eccentric stenoses from exertion of dilating pressures.

Results: Dilating pressures depend directly on maximal balloon inflation pressure and balloon diameter. Short, focal stenoses experience greater dilating pressures, which often are several multiples of the inflation pressure, than similarly narrowed longer lesions.

Conclusion: Dilating pressures depend on inflation pressure, balloon diameter, and lesion severity.