Background and Goal of Study:
Factor XI (FXI) deficiency is a rare inherited bleeding disorder characterized by bleeding manifestations of variable severity not correlated with the baseline FXI:Act. The aim of this study was to evaluate the perioperative management of patients with FXI deficiency. We investigated haemorrhagic complications according to the surgery and the applied prophylactic measures. This study has been approved by our Ethical Committee.

Materials and Methods:
Medical files of patients with FXI deficiency diagnosed at Cliniques Universitaires Saint-Luc, Brussels, Belgium between 2005 and 2017 (56) were analyzed. All haemostatic challenges that the patients underwent before and after diagnosis were analyzed retrospectively.

Results and Discussion:
We investigated 56 FXI-deficient patients; 19 patients with a mild (FXI:Act: 50-70%), 30 patients a moderate (15-49%) and 7 patients a severe deficiency (<15%). 21 patients (38%) had an associated haemostatic disorder and only 37 (66%) had a prolonged APTT.
Reasons for diagnosis were prolonged APTT (30%), family screening (36%) and bleeding history (34%). Prior to diagnosis, 35 patients had undergone 77 procedures with 31 (40%) of them associated with excessive bleeding. 28 (90%) of these procedures occurred on sites with high fibrinolytic activity. There was no significant difference in FXI:Act between bleeders and non-bleeders (P=0.62).
After diagnosis, 31 patients underwent 35 surgeries. All surgeries, except for 4, were prophylactically treated with tranexamic acid (TA) alone (n= 27) or combined with fresh frozen plasma (FFP) (n=4). 5 (14%) patients presented a haemorrhagic complication and were treated with FFP; 2 patients needed surgical revision whereas 2 others needed RBC transfusion. 3 bleeding events occurred during surgeries on sites with high fibrinolytic activity and 2 occurred in patients with an associated haemostatic disorder.

Conclusion(s):
Patients with FXI deficiency may present variable bleeding risks not correlated with FXI:Act. Optimal perioperative haemostatic management requires attention to the bleeding tendency, the nature and the site of the procedure and the presence of associated haemostatic disorders. Prophylactic treatment with TA is certainly needed to reduce the risk of bleeding complications. In case of excessive bleeding, treatment should include FFP and/or FXI-concentrate. 


06 / Perioperative haemostatic management of patients with FXI deficiency: a single center retrospective study