Patients with retained transcranial knife blades: a high-risk group.

Sixty-six patients with transcranial stab wounds presenting to Groote Schuur Hospital over a 2-year period are reviewed. Two groups were identified, those with retained knife blades at presentation (Group A, 13 patients) and those without (Group B, 53 patients). An increased incidence of vascular complications was observed in Group A, (eight of 13 patients) compared with 11 of 53 patients in Group B (p < 0.01, chi-square test). The mortality rate was also higher in Group A, with deaths in three of 13 patients compared with four of 53 in Group B. Increased mortality was a result of vascular injury, and in two patients neurological deterioration occurred only after knife blade removal. Possible reasons for these findings are that retained blades tend to be deeply penetrating with a potential for more cerebral and vascular injury, and there is a higher incidence of petrous bone penetration that results in carotid artery injury.