Mary Sheridan Bilbao, PA-C, FAPACVS, is an accomplished advanced practice provider specializing in Cardiothoracic Surgery. She earned both her Undergraduate degree and Masters of Physician Assistant Studies at Marywood University. With extensive experience in cardiothoracic surgery, Mary became an integral part of our team in 2014.

Her expertise spans both in-patient and outpatient care, where she actively participates in surgical procedures and contributes to various studies and laboratory research. Mary's proficiency extends to open and endoscopic vein harvesting, radial artery harvesting, valve replacements, minimally invasive aortic and mitral valve repair/replacements, ascending aorta/aortic dissection/aortic arch repair/replacements, redo surgeries, coronary artery bypass grafting (off and on-pump), robotic-assisted minimally invasive coronary artery bypass grafting, minimally invasive myocardial bridge unroofing, heart/lung transplants, VADs, and ECMO.

Beyond her clinical duties, Mary plays a crucial role in training new PAs, NPs, APP fellows, residents, and medical students in various surgical skills. In the clinic, she performs history & physicals, pre-op evaluations, orders/interprets studies & labs, and coordinates in-patient and out-patient care.

Since January 2015, Mary has been the driving force behind the Stanford Department of Cardiothoracic Surgery's Human Biorepository Tissue Bank. This initiative has amassed over 1,000 human cardiothoracic tissue samples, fostering approved studies to advance cardiovascular and pulmonary disease research. Collaborating with over 30 partners and Stanford labs, Mary's goal is to facilitate research by providing cardiothoracic tissue samples to researchers and scientists across Stanford Medicine.

Currently, Mary holds the position of Principal Academic and Clinical Integration Developer in the CT Surgery Department, further highlighting her leadership role in our institution. In this capacity, she plays a pivotal role in curating and developing marketing materials and outreach strategies for the department. Mary's dedication extends beyond clinical excellence; she actively contributes to fostering academic growth and enhancing the department's visibility. Her strategic approach to marketing ensures that the department's achievements and advancements in cardiothoracic surgery are effectively communicated to the broader medical community and the public, reinforcing our commitment to excellence in patient care, research, and education.

Furthermore, Mary has been an esteemed member of Dr. Joseph Woo's Stanford Advanced Cardiovascular Therapeutics and Surgical Biomechanics Translational Research Laboratory (Woo Lab) since 2012. Her involvement in numerous clinical trials and published research underscores her commitment to advancing the field of cardiovascular medicine. Learn more about Woo Lab at

Clinical Focus

  • Physician Assistant
  • Cardiac
  • Cardiac Surgery

Professional Education

  • Board Certification: National Commission on Certification of Physician Assistants, Physician Assistant (2009)
  • Professional Education: Marywood University (2009) PA
  • Professional Education: Marywood University (2008) PA

All Publications

  • Endoscopic Radial Artery Harvesting During Anesthesia Line Placement Reduces the Time and Cost of Multivessel Coronary Artery Bypass Grafting. Innovations (Philadelphia, Pa.) Wang, H., Bilbao, M. S., Miller, S. L., O'Donnell, C. T., Boyd, J. H. 2020: 1556984519882014


    OBJECTIVE: Endoscopic radial artery (RA) harvesting performed concurrently with internal mammary artery (IMA) takedown and endoscopic saphenous vein (SV) harvesting creates a crowded and inefficient operating room environment. We assessed the effect of a presternotomy RA harvest strategy on surgery time and costs.METHODS: A total of 41 patients underwent elective, first-time, isolated multivessel on-pump coronary artery bypass grafting including an IMA, RA, and SV graft. The first 20 patients (Phase I) underwent endoscopic RA harvesting concurrently with IMA takedown and endoscopic SV harvesting after sternotomy, requiring two sets of endoscopic harvesting equipment per case, each used by a separate individual. The final 21 patients (Phase II) underwent endoscopic RA harvesting during anesthesia line placement, completing the procedure before sternotomy, thus requiring only one set of endoscopic harvesting equipment reused by a single individual.RESULTS: There were no differences in baseline patient characteristics, number of bypasses, duration of SV or RA harvest time, or duration of cardiopulmonary bypass or cross-clamp time between the two groups. Total surgery time was reduced by 32 minutes in Phase II (P = 0.044). Relative to a total hospital direct cost of 100.00 units, total surgery costs were reduced from 29.33 units in Phase I to 25.62 units in Phase II (P = 0.001). No anesthesia- or RA harvest-related complications occurred in either group.CONCLUSIONS: Endoscopic RA harvesting can be safely performed during anesthesia line placement prior to sternotomy. Our simple but innovative strategy improves intraoperative workflow, reduces the time and cost of surgery, and advances the delivery of high-quality patient care.

    View details for DOI 10.1177/1556984519882014

    View details for PubMedID 31903868

  • Autograft Valve-Sparing Root Replacement for Late Ross Failure during Quadruple-Valve Surgery ANNALS OF THORACIC AND CARDIOVASCULAR SURGERY Goldstone, A. B., Jensen, C. W., Bilbao, M., Woo, Y. 2017; 23 (6): 313–15


    Approximately 25% of patients require reoperation within 15 yrs of a Ross procedure. Increasing experience with valve-sparing root replacement (VSRR) has led some surgeons to spare the autograft valve. Here, we demonstrate that all valves can be surgically repaired or replaced safely during autograft VSRR. As more patients are considered for this operation, coexistent mitral, tricuspid, and pulmonic valve dysfunction should not preclude salvage of the autograft valve, nor should autograft leaflet prolapse.

    View details for PubMedID 29046487

  • Minimally invasive mitral valve repair in situs inveresus totalis Journal of Cardiac Surgery Goldstone, MD, A. B., Patrick BS, W. L., Bilbao, PA-C, M. S., Woo, MD, Y. 2016 ; Vol 31 (12): 718-720
  • Quantitative evaluation of change in coexistent mitral regurgitation after aortic valve replacement 38th Annual Meeting of the Western-Thoracic-Surgical-Association Kaczorowski, D. J., MacArthur, J. W., Howard, J., Kobrin, D., Fairman, A., Woo, Y. J. MOSBY-ELSEVIER. 2013: 341–48


    Management of intermediate degrees of mitral regurgitation during aortic valve replacement for aortic stenosis remains controversial. We sought to evaluate the degree of reduction of mitral regurgitation in patients undergoing aortic valve replacement, as well as a mathematical relationship between aortic valve gradient reduction and the degree of mitral regurgitation decrement.We retrospectively analyzed demographic, intraoperative, and echocardiographic data on 802 patients who underwent aortic valve replacement or aortic root replacement between January 2010 and March 2011. A total of 578 patients underwent aortic valve replacement or aortic root replacement without intervention on the mitral valve. We excluded 88 patients with severe aortic insufficiency, 3 patients who underwent ventricular assist device placement, 4 patients who underwent prior mitral valve replacement, and 21 patients with incomplete data, yielding 462 patients for analysis. For each patient, the degree of pre- and postoperative mitral regurgitation was graded on a standard 0 to 4+ scale.Of the 462 patients, 289 patients had at least mild mitral regurgitation. On average, mitral regurgitation decreased 0.24 degrees per patient for this cohort of 289 patients. Of the 56 patients with at least moderate mitral regurgitation, mitral regurgitation decreased 0.54 degrees per patient. Of 62 patients who underwent isolated aortic valve replacements, who had at least mild mitral regurgitation, and who had no evidence of structural mitral valve disease, mitral regurgitation decreased 0.24 degrees per patient. Linear regression analysis revealed no relationship between reduction in mitral regurgitation and gradient reduction across the aortic valve.Reduction in mitral regurgitation after relief of aortic outflow tract obstruction is modest at best. Further, the magnitude of gradient change across the aortic valve has little influence on the degree of reduction in mitral regurgitation. These observations argue at minimum for performing a prospective evaluation of the clinical benefits of addressing moderate mitral regurgitation at the time of aortic valve intervention and may support a more aggressive approach to concomitant mitral surgery.

    View details for DOI 10.1016/j.jtcvs.2012.10.043

    View details for Web of Science ID 000313634700010

    View details for PubMedID 23245347

    View details for PubMedCentralID PMC3660734