Fibrinogen but not factor XIII deficiency is associated with bleeding after craniotomy.

Postoperative haemorrhage in neurosurgery is associated with significant morbidity and mortality. There is controversy whether or not factor XIII (FXIII) deficiency leads to bleeding complications after craniotomy. Decreased fibrinogen levels have been associated with an increased incidence of bleeding complications in cardiac and orthopaedic surgery. The aim of this study was to assess perioperative fibrinogen and FXIII levels in patients undergoing elective intracranial surgery with and without severe bleeding events. Perioperative FXIII and fibrinogen levels were prospectively assessed in 290 patients undergoing elective craniotomy. Patients were divided into two groups according to the presence or absence of severe bleeding requiring surgical revision. Coagulation test results of these groups were compared using Student's t-test. The incidence of postoperative severe bleeding was 2.4%. No differences in FXIII levels were observed, but postoperative fibrinogen levels were significantly lower in patients suffering from postoperative haematoma compared with those without postoperative intracranial bleeding complications [237 mg dl(-1) (standard deviation, SD 86) vs 170 mg dl(-1) (SD 35), P=0.03]. The odds ratio for postoperative haematoma in patients with a postoperative fibrinogen level below 200 mg dl(-1) was 10.02 (confidence interval: 1.19-84.40, P=0.03). This study emphasizes the role of fibrinogen as potentially modifiable risk factor for perioperative bleeding in intracranial surgery. Future randomized controlled trials will be essential to identify patients who might benefit from fibrinogen substitution during neurosurgical procedures.