Every coronary stent procedure hinges on a number that rarely gets discussed outside the cath lab: pressure, measured in atmospheres, applied through an inflation device to expand a balloon and stent inside the artery. Getting stent deployment pressure right is not a minor technical detail. Too little pressure and the stent may not fully expand against the vessel wall; too much, and the balloon risks exceeding its structural limits. Two figures anchor this process for every device: nominal pressure and rated burst pressure, both defined by the manufacturer and printed on every balloon or stent delivery system's packaging.
What Does Nominal Pressure Actually Mean?
Nominal pressure is the inflation pressure at which a balloon, and by extension the stent mounted on it, is expected to reach its labeled diameter under standard test conditions. This figure serves as a practical reference point for the physician performing the procedure, since it represents the pressure typically needed to achieve the device's intended expanded size. Nominal pressure is not necessarily the pressure used in every case, since actual vessel anatomy, calcification, and lesion resistance can require adjustment, but it establishes a baseline that guides initial inflation strategy.
How Is Rated Burst Pressure Different From Nominal Pressure?
Rated burst pressure is the upper pressure threshold above which the manufacturer does not guarantee the structural integrity of the balloon. It is generally established through statistical testing so that, per standard practice in the industry, a defined percentage of balloons are expected to withstand pressures at or below this figure without rupture. This is fundamentally a safety ceiling rather than a target. Physicians are trained to stay below rated burst pressure during a procedure, and balloon labeling makes this figure clearly available precisely because working near or above it changes the risk profile of the inflation.
Why Do Physicians Use a Balloon Compliance Chart During the Procedure?
A balloon compliance chart maps out how a specific balloon's diameter changes as inflation pressure increases, since balloons are not rigid structures and will expand somewhat beyond their nominal diameter as pressure rises. This chart is a practical tool used during the procedure to help a physician select an inflation pressure that achieves a target vessel diameter without inadvertently approaching rated burst pressure. Because compliance behavior differs from one balloon design to the next, the chart is specific to each device and is included in that product's technical documentation and Instructions for Use.
What Happens During Post-Dilation?
Post-dilation refers to a second balloon inflation performed after stent deployment, generally intended to further optimize how well the stent struts are pressed against the vessel wall, a property often described as stent apposition. This step is commonly used when the physician determines that additional expansion is needed to address residual narrowing or incomplete strut apposition seen on imaging. As with initial deployment, post-dilation pressure is selected with reference to the compliance chart and rated burst pressure of the balloon being used, since exceeding these limits is generally avoided regardless of which stage of the procedure is underway.
The ATLAS System's Reported Pressure Specifications
The ATLAS Drug Eluting Coronary Stent System, manufactured by INVAMED, has a nominal pressure reported by the manufacturer at 9 to 10 atm and a rated burst pressure reported at 14 to 16 atm. These figures, along with the device's compliance chart and complete deployment instructions, are detailed in the Instructions for Use (IFU) available on the ATLAS Drug Eluting Coronary Stent System product page. Availability and specific indications vary by country, and the current IFU should always be consulted before use. General information about the broader device category is also available on the INVAMED coronary artery disease and cardiac interventions product page.
What happens if a balloon is inflated above its rated burst pressure?
Exceeding rated burst pressure increases the statistical likelihood of balloon rupture or failure during the procedure, which is why manufacturers define this figure and physicians are trained to remain below it. Specific pressure limits vary by device and are detailed in each product's Instructions for Use.
Is nominal pressure the same for every balloon size?
No, nominal pressure and rated burst pressure are specific to each balloon or stent delivery system design and can vary by diameter, length, and manufacturer. These figures should always be confirmed from the specific device's labeling rather than assumed from a different product.
Who decides how much pressure to use during a procedure?
The treating physician determines appropriate inflation pressure during a procedure, guided by the device's compliance chart, its rated burst pressure, and the specific vessel anatomy being treated. This is a clinical judgment made in real time and is not a fixed, one-size-fits-all figure.
Device availability and regulatory status vary by country. Please contact INVAMED or your authorized local distributor for current regulatory information applicable to your region.