Parasternaler vs. Sternotomie-Zugang bei konventionellem Aortenklappenersatz - PASTA Trial
Deutsche Stiftung für Herzforschung
The classic surgical treatment of aortic stenosis is valve replacement through complete midline opening of the breastbone (median sternotomy) and use of cardiopulmonary bypass (CPB). Risks of this procedure are related to both the surgical approach and the use of CPB. Using minimally invasive approaches in non-cardiac patients (e.g laparoscopy) resulted in reduced postoperative inflammatory response when compared to patients undergoing the same procedures carried out with a conventional "open" technique. Minimally invasive surgical approaches in which the sternum is partially opened (partial sternotomy) or not opened at all (parasternal access) have thus far shown similar procedure related mortality and lower incidence of perioperative complications, despite longer CPB times. Our single center experience thus far suggests superiority of parasternal aortic valve replacement (O/E ratio of 0.19 over the last 2 years), as well as a reduced postoperative inflammatory response (as measured by lower CRP (C reactive protein ) levels taken 6 hours post-surgery). However, these data have several confounders and there is currently no prospective randomized trial addressing this topic. We therefore conduct a randomized comparison of parasternal versus classic sternotomy aortic valve replacement. Based on our previous experience, we expect very low mortality risk in both groups (expected ? 1%). The primary endpoint is therefore quality of life assessed using the SF-36 (Short Form) health survey questionnaire. This approach is similar to other current large multicenter trials. In order to address the impact of reduced surgical trauma on inflammatory response; we will quantify an established panel of inflammatory markers (PCT, CRP, interleukin 6) and use bio-banking to allow for further in depth analysis later on. Standardized clinical endpoints will be analyzed as additional secondary parameters. Power analysis determined a number of 50 patients allocated to 2 equal groups to achieve a power of 80%. The parasternal approach is expected to be superior when compared to sternotomy in both the primary and some, if not most, secondary endpoints. We expect our study to become an important milestone for decision-making in the treatment of aortic stenosis. Patients currently fear sternotomy, but the less invasive transcatheter valve implantation appears to be limited by inferior long-term outcome. The parasternal, sternotomy-sparing, classic aortic valve replacement is therefore an attractive therapeutic alternative. Our investigation in relation to systemic inflammatory response will further shed light on the underlying mechanisms explaining differences in clinical outcomes.