= Vascular graft burst pressure
\b[Vascular graft burst pressure] is the internal-to-external <pressure difference> at which a <vascular graft> fails by rupture in a specified pressurization test. It is a destructive strength measurement. The <vascular graft burst-test conditions>, including mounting, surrounding pressure, pressure ramp and failure location, are needed to interpret the reported number. Leakage at a connector and rupture of the graft wall are different observed events.
An elementary <thin-walled pressure vessel> calculation explains the role of geometry. Cut a cylindrical tube of radius $r$, wall thickness $h$ and length $L$ along its axis. The resultant pressure force on a half-cylinder is $2rL\,\Delta p$, balanced by two cut walls carrying $2hL\,\sigma_\theta$. Thus the <hoop stress> is
$$
\sigma_\theta=\frac{\Delta p\,r}{h}.
$$
If a stipulated wall failure stress is $1\,\mathrm{MPa}$, $h=0.20\,\mathrm{mm}$ and $r=2.0\,\mathrm{mm}$, this model predicts
$$
\Delta p_{\rm fail}\approx\frac{\sigma_{\rm fail}h}{r}=100\,\mathrm{kPa}\approx750\,\mathrm{mmHg}.
$$
This is an illustrative membrane-force balance, not a measured graft specification. It assumes a thin, uniform wall and ignores local defects, changing radius, nonlinear material response and attachment effects. The measured rupture pressure need not equal this estimate.
The primary engineered-bovine-artery study measured rupture strength as well as static and dynamic mechanical response within 24 hours of harvesting vessels. Those were distinct endpoints, rather than interchangeable definitions of graft quality.<Morphologic and mechanical characteristics of engineered bovine arteries by Laura E. Niklason and others>[Printed pp. 631–632: bench-top mechanical measurements; mechanical-strength Results]{ref}
A graft that survives a particular pressure test has not thereby demonstrated a specified <graft patency> or repeated-loading lifetime. Conversely, a burst-pressure comparison alone does not measure <vascular graft compliance mismatch>. A useful report separates the observed failure event, its pressure difference and the test conditions from predictions about subsequent biological performance.
Back to article page
