Study Design
This was a prospective, single center, observational study comparing patients undergoing surgery for ATAAD with a control group consisting of patients undergoing elective aortic surgery of the ascending aorta and/or the aortic root. The ATAAD group consisted of patients over the age of 18 with symptom duration <48h undergoing surgery for ATAAD at Skåne University Hospital, Lund, Sweden, between September 2015 and April 2018. ATAAD was confirmed by contrast-enhanced computed tomography. The anatomical extent of the dissection was defined according to the Stanford 18 and Debakey19 classification. Exclusion criteria were preoperative use of anti-coagulants or anti-platelet drugs other than aspirin (both groups) and if surgical approach deviated from routine (as described below) (ATAAD group).
All patients with acute aortic syndromes (e.g. ATAAD and intramural hematomas) referred to our clinic during the study period were registered and screened for inclusion (Fig 1). Routinely, a ROTEM Delta (Tem Innovations GmgH, Germany) and standard lab test guided bleeding management protocol was used at our clinic (Fig 2). Red blood cell transfusions were given at B-Hemoglobin <90g/L. Platelets were administered at maximum clot firmness (MCF) EXTEM <50mm and MCF FIBTEM >10mm or platelet count <100x109/L. Fibrinogen and/or plasma were used at MCF FIBTEM <15mm or P-fibrinogen <2g/l. Plasma or prothrombin complex concentrate (PCC) were used at coagulation time (CT) EXTEM >100s, CT INTEM >240s, P-PT(INR) >1.5 or P-APTT >1.5 x normal value. Additional Tranexamic acid was used when maximum lysis (ML) exceeded 15%. However, final decision regarding transfusions was at the surgeon’s discretion.