April 28, 2025 — The Society of Thoracic Surgeons (STS) has launched its latest surgical risk calculator designed for patients undergoing ascending aorta and aortic root surgery, with or without concomitant aortic valve replacement (AVR). This first-of-its-kind tool represents a major step forward in risk stratification and personalized surgical planning for complex aortic operations.
Developed using data from more than 67,000 adult ascending aorta and aortic root surgeries submitted to the STS Adult Cardiac Surgery Database (ACSD) between July 2017 and December 2024, the new calculator provides individualized operative risk estimates for four key procedural groups:
1. Bentall procedures involving AVR
2. Ascending aorta plus AVR
3. Valve-sparing root replacement
4. Isolated ascending aorta surgery
The risk calculator supports more accurate assessments of expected outcomes, including mortality and major morbidity, based on real-world data collected through STS’s expanded aorta surgery module.
“This risk calculator fills a critical gap for cardiothoracic surgeons treating complex aortic pathology,” said STS President Joseph F. Sabik III, MD. “It empowers surgeons to have more transparent, productive conversations with patients and families about surgical risks and benefits, leading to better-informed decision making.”
Aortic operations accounted for nearly 11.2% of all major cardiac surgeries in the United States in 2024, up from 8.3% in 2018—a trend that underscores the growing need for tailored decision-support tools in this area. Until now, surgeons lacked a validated method to assess operative risk for ascending aorta and aortic root procedures at the bedside.
In addition to its clinical utility, the mobile-friendly calculator is expected to support the design and evaluation of new clinical trials and comparative studies, particularly those exploring the outcomes of traditional surgery versus less invasive procedures.
"This new tool is not only a clinical asset, but also a catalyst for research,” added Dr. Sabik. “It will support the design and evaluation of new clinical trials and studies, especially those comparing open aortic surgery to less invasive alternatives, a critical and growing area of interest in cardiovascular care.”
The risk models implemented in this tool are based on the study, “Development of a Novel Society of Thoracic Surgeons Aortic Surgery Mortality and Morbidity Risk Model,” published in The Annals of Thoracic Surgery. The study describes the methodology and validation behind the risk stratification framework.
The ACSD is part of the STS National Database, one of the largest and most comprehensive clinical registries in health care. With nearly 10 million cardiothoracic procedures submitted by more than 4,300 surgeons, the STS Database captures over 95% of adult and congenital cardiac surgery procedures performed in the United States, along with a majority of lung and esophageal cancer surgeries. As a result, the STS Database provides true national benchmarks for clinical outcomes in cardiothoracic surgery.
The Ascending Aorta and Aortic Root Surgery Risk Calculator is the latest in a series of enhancements to the STS National Database designed to meet the day-to-day needs of surgeons and cardiothoracic care teams. It joins a trusted portfolio of STS adult cardiac surgery risk calculators that provide individualized risk assessments for procedures such as isolated tricuspid valve repair and replacement; surgical aortic valve replacement (SAVR) after prior transcatheter aortic valve replacement (TAVR); and multi-valve surgery with or without coronary artery bypass grafting (CABG). These tools predict outcomes such as mortality, stroke, and length of hospital stay.
This launch reinforces STS’s commitment to delivering high-impact resources that support surgeon excellence and innovative cardiovascular research.
December 24, 2025 
