Risk factors for hemorrhage during microelectrode-guided deep brain stimulation and the introduction of an improved microelectrode design

OBJECTIVE: Hemorrhage is an infrequent but potentially devastating complication of deep brain stimulation (DBS) surgery. We examined the factors associated with hemorrhage after DBS surgery and evaluated a modified microelectrode design that may improve the safety of this procedure. METHODS: All microelectrode-guided DBS procedures performed at our institution between January 2000 and March 2008 were included in this study. A new microelectrode design with decreased diameter was introduced in May 2004, and data from the 2 types of electrodes were compared. RESULTS: We examined 246 microelectrode- guided lead implantations in 130 patients. Postoperative imaging revealed 7 hemorrhages (2.8%). Five of the 7 (2.0%) resulted in focal neurological deficits, all of which resolved within 1 month with the exception of 1 patient lost to follow-up. The new microelectrode design significantly decreased the number of hemorrhages (P = 0.04). A surgical trajectory traversing the ventricle also contributed significantly to the overall hemorrhage rate (P = 0.02) and specifically to the intraventricular hemorrhage rate (P = 0.01). In addition, the new microelectrode design significantly decreased the rate of intraventricular hemorrhage, given a ventricular penetration (P = 0.01). The mean age of patients with hemorrhage was significantly higher than that of patients without hemorrhage (P = 0.02). Hypertension, sex, and number of microelectrodes passed did not significantly contribute to hemorrhage rates in our population. CONCLUSION: The rate of complications after DBS surgery is not uniformly distributed across all cases. In particular, the rates of hemorrhage were increased in older patients. Importantly, transventricular electrode trajectories appeared to increase the risk of hemorrhage. A new microelectrode design minimizing the volume of brain parenchyma penetrated during microelectrode recording leads to decreased rates of hemorrhage, particularly if the ventricles are breached.