Postoperative complications after redo valve surgery

Purpose: To analyze causes and patterns of multiple organ dysfunction syndrome in the postoperative period after redo valve surgery. Materials and Methods: Medical records of 153 patients, consecutively admitted to the hospital from 2003 to 2012 to undergo reoperation for prosthetic heart valve dysfunction, were retrospectively reviewed. The New York Heart Association (NYHA) class IV heart failure with circulatory failure class IIB and MK IIB was found in 133 patients (86.9%); NYHA class III was found in 11 patients (7.2%); and NYHA class II was found in 9 patients (5.9%). All patients received standard background therapy. Patients were assigned to two groups: study group (n=51) with postoperative multiple organ dysfunction syndrome (MODS) and control group (n=102) without MODS. Within-group and between-group analyses of clinical parameters were performed (organ dysfunction incidence rate; organ dysfunction patterns; time of the ICU stay; and mortality rate). Results: 51 patients (33.3%) reported MODS; 102 patients (66.7%) demonstrated uncomplicated postoperative period or the presence of one organ/system dysfunction. The underlying pathologies as well as gender- and age-dependent differences did not affect the MODS incidence rate. Development of MODS was observed when two or more risk factors were present, mostly in cases with prolonged bypass time (min - 118 min, max - 194 min) and transfusion of more than four units of blood components (39 cases, 76.5%: moderate positive relationship, r=0.355; p=0.01). Despite MODS incidence rate did not depend on surgical caseload (r=-0.205; p=0.029) it determined the overall mortality rate (r=0.31; p=0.013) and time of the ICU stay for survivors (11.2 days vs. 5.6 days with and without MODS, respectively; p=0.011). No relationship between MODS and surgical caseload was found (r=-0.295; p=0.0333); the total mortality rate was determined by development of MODS in the postoperative period (r=0.715; p=0.0155); the risk of death was significantly higher when dysfunction of three or more organs/systems was present.