The ross procedure: a systematic review and meta-analysis

In young adult patients with aortic valve disease treated with conventional aortic valve replacement (AVR), expected lifespan post-operatively is decreased by up to 20 years. The Ross procedure presents an alternative to conventional treatment that aims to provide a durable valve substitute without the need for lifelong anticoagulation. Recent evidence suggests the Ross procedure may restore life expectancy equivalent to that of the age- and gender-matched general population. However, concerns regarding increased perioperative risk and early pulmonary valve re-intervention have limited its uptake. In this systematic review and meta-analysis, we aimed to compare the Ross procedure to conventional AVR with regards to mortality, reintervention, and adverse valve-related events. We searched MEDLINE, EMBASE, and Cochrane CENTRAL from inception to February 2017 for observational studies (n>50) or randomized controlled trials (RCTs) evaluating the Ross procedure compared to any conventional AVR (including homograft, mechanical, and biologic prostheses) in adult patients (≥16 years of age). We performed screening, full-text assessment, risk-of-bias evaluation and data-collection independently and in duplicate. We evaluated risk-of-bias for observational studies with the ROBINS-I tool and with the Cochrane tool for RCTs, assessed quality of evidence with the GRADE framework and pooled data using a random effects model. Twelve observational cohort studies and two RCTs were identified (n=5456). Only two observational studies were considered to be at low risk of bias. The Ross procedure was associated with a decrease in mortality at latest follow-up in both observational (mean follow-up = 3.6 years) and RCT (mean follow-up = 10.4 months) data; respectively RR 0.50 (95%CI[0.31,0.80], I2=68%, very low quality) and RR 0.51 (95%CI[0.06,4.64], I2=66%, low quality). We found no significant difference in the risk for operated valve reintervention in observational studies (RR 1.45, 95%CI[0.87,2.42], I2=55%, very low quality] and RCTs (RR 0.86, 95%CI[0.07,11.46], I2=68%, low quality). In a subgroup analysis stratifying based on conventional AVR comparator type mortality benefit persisted when compared to mechanical valves alone and reoperation results were consistent in all subgroups. Based on very low quality observational evidence and limited RCT data, the Ross procedure provides significant mortality benefit with no increased risk for reoperation when compared to conventional AVR options. Although high-quality randomized literature is required to validate these findings before stronger recommendations can be made, the Ross procedure appears safe for use in young adult patients and should be discussed with patients at the time of operative planning and decision-making.