Venous air embolism in deep brain stimulation.

BACKGROUND/AIMS: During the placement of electrodes for deep brain stimulation (DBS), patients are commonly in a seated position, awake, and spontaneously breathing. Air may be entrained through bone or dural veins causing venous air emboli (VAE) and this phenomenon can result in significant hemodynamic changes. Although VAEs have been described in many types of neurosurgical procedures, their incidence during DBS surgery is unknown.

METHODS

Following approval from the Institutional Review Board, the University of Florida Movement Disorders Center database comprising 286 DBS leads placed since 2002 was reviewed. Intraoperative cough, which has been associated with VAE, as well as hemodynamic instability were the focus of the review. Additionally, a prospective evaluation of the incidence of VAE using precordial Doppler ultrasound was undertaken over a 3-month period (June 2007-August 2007).

RESULTS

The retrospective review revealed a 3.2% incidence of cough per lead. Prospective monitoring in 21 consecutive patients with 22 leads yielded the detection of 1 VAE, and an incidence of 4.5% per lead.

CONCLUSION

VAEs are rare but potentially serious complications of DBS surgery unless recognized. Patient positioning and the occurrence of cough are two important predictors to consider in VAE. Precordial Doppler is a safe, non-invasive monitor that can be used in the early detection of VAE in these procedures.