Template bleeding time for preoperative screening in patients having orthognathic surgery.

Excessive blood loss is a serious but rare complication of orthognathic surgery. The aim of this study was to find out whether template bleeding time (TBT) could detect primary bleeding disorders in patients having orthognathic operations and how many false positive tests there were. We also examined the correlation between the perioperative bleeding rate and the result of preoperative TBT. Patients who had orthognathic operations at Karolinska University Hospital, Huddinge, from August 2001 to December 2006, were screened preoperatively by measuring TBT and the records of their operations were reviewed retrospectively. Prolonged TBT was recorded in 20 patients (13%), 19 female and 1 male (P=0.02). After further examination, 10 of these patients were found to have a primary disorder of haemostasis. No detectable reason for the prolonged TBT could be found in the others. There was no significant difference in perioperative bleeding rate between patients with prolonged and normal TBT or between TBT and perioperative bleeding rate. In conclusion, the routine use of preoperative TBT for haemostatic screening in orthognathic surgery cannot be recommended because of the large number of false positive results. There was no significant correlation between prolonged TBT and bleeding during orthognathic surgery.