High postoperative portal venous flow pulsatility indicates right ventricular dysfunction and predicts complications in cardiac surgery patients

Abstract

Background: Right ventricular failure after cardiac surgery is associated with morbidity and mortality. Right ventricular dysfunction results in hepatic venous congestion, which impacts the portal circulation. We aimed to determine whether an increased portal flow pulsatility fraction was associated with right ventricular dysfunction in cardiac surgery patients. We also aimed to describe the haemodynamic factors and postoperative complications associated with an increased portal pulsatility in this setting.

Methods: We conducted a prospective single-centre cohort study, recruiting adults undergoing cardiac surgery. Portal flow was assessed before, during, and after surgery by Doppler ultrasound. A detailed haemodynamic and echocardiographic assessment was performed at the same time points.

Results: A total of 115 patients were included. Both systolic and diastolic right ventricular dysfunction were associated with a higher portal pulsatility fraction (P=0.008 and <0.001, respectively). A positive association was present between portal pulsatility fraction and measurements representative of venous pressure (central venous pressure, inferior vena cava diameter). A post-procedural portal pulsatility fraction ≥50% measured in the operating room was present in 21 (18.3%) patients and was associated with an increased risk of major complications (odds ratio=5.83, confidence interval, 2.04-16.68, P=0.001). The addition of portal flow assessment to a predictive model including EuroSCORE II and systolic right ventricular dysfunction improved prediction of postoperative complications.

Conclusions: High portal flow pulsatility fraction is associated with right ventricular dysfunction, signs of venous congestion and decreased perfusion, and an increased risk of major complications. Portal vein Doppler ultrasound appears to be promising for risk assessment in the perioperative period.

Clinical trials registration: NCT02658006.

Keywords: cardiac surgery; echocardiography; thoracic surgery; ultrasonography, Doppler; ventricular dysfunction, right; ventricular function..