Lead revision surgery for vagus nerve stimulation in epilepsy: Outcomes and efficacy Hena Waseem a , Scott J. Raffa a , Selim R. Benbadis b , Fernando L. Vale a, ⁎ a Department of Neurosurgery and Brain Repair, Morsani College of Medicine, University of South Florida, 2 Tampa General Circle, USF Health, 7th Floor, Tampa, FL 33606, USA b Department of Neurology, Morsani College of Medicine, University of South Florida, 2 Tampa General Circle, USF Health, 6th Floor, Tampa, FL 33606, USA abstract article info Article history: Received 2 September 2013 Revised 29 November 2013 Accepted 2 December 2013 Available online 3 January 2014 Keywords: Vagus nerve stimulation Intractable epilepsy Seizure disorder Epilepsy surgery Lead revision We present, to our knowledge, the first published analysis of vagus nerve stimulation (VNS) lead revisions to incorporate quality of life, clinical response, and antiepileptic drug (AED) burden in postrevision clinical out- comes. Ten patients were followed and had no postoperative complications. Seven patients had improvement in quality of life, and three experienced no change. Eight patients noted a restoration of clinical response compa- rable with initial VNS implantation. Seven patients reported 30–60% improvement in seizure reduction, two ex- perienced N 60%, and one noted b 30%. Six patients had no change in AED burden. Vagus nerve stimulation lead revision should be considered a safe option for patients with VNS lead failure and medically intractable epilepsy. © 2013 Elsevier Inc. All rights reserved. 1. Introduction Vagus nerve stimulation (VNS), first investigated in 1938 and subse- quently studied as a potential therapy for epilepsy, has since been ap- proved as an effective means of seizure control in patients with intractable epilepsy [1–6]. While the precise mechanism of action is not well understood, VNS is known to modify cerebral electrical activity through thalamocortical pathways [7]. Currently accepted as an adjunct therapy to reduce seizure frequency in patients 12 years of age and older with refractory partial-onset seizures, VNS is suggested to be also effective in treating generalized epilepsy in children younger than 12 years of age [8–11]. Recent studies have investigated the utility of VNS in treating other conditions, including heart failure, depression, Alzheimer's disease, and migraine disorders [12–15]. In patients whose seizures have remained unresponsive to medical and surgical therapy for epilepsy, VNS can increase quality of life, reduce seizure frequency, and potentially reduce antiepileptic drug (AED) bur- den [16]. Once introduced, VNS can decrease seizure activity by approx- imately 30% [4–6]. Since FDA's approval of VNS in 1997, more than 65,000 VNS devices have been implanted worldwide, and the use of VNS for treatment of intractable epilepsy has remained consistent [17]. Despite their effectiveness, VNS implants are mechanical devices, and material failure occurs. In some circumstances, complete removal of the VNS may be appropriate. Procedures for the surgical revision of the pulse generator and lead cable have been detailed and continue to be discussed [18–20]. Generator replacement is a routine procedure with low risk. Lead revision is infrequently performed and considered more challenging, primarily because of the scar tissue often found encasing the helical electrodes wrapped around the vagus nerve. Research supports the safety of lead revision, but evidence is limited regarding surgical technique and postoperative complications. This study presents 14 patients with VNS lead failure and evaluates out- comes and efficacy of lead revision as performed in 10 of the 14 cases. We report that VNS lead revision surgery can be performed safely and without complication, with patients experiencing seizure control and quality of life comparable with initial VNS implantation. 2. Methods 2.1. Patient selection A review of surgical cases conducted at our institution between January 1988 and June 2013 identified 263 patients 12 years of age or older who underwent VNS surgery. Patient data included age, indica- tions for lead revision, number of AEDs prerevision and postrevision, and date of initial VNS implantation. All cases were performed by a sin- gle neurosurgeon (FLV). Patients had successfully completed a preoper- ative comprehensive epilepsy evaluation based on a relatively standard protocol algorithm, which included a complete history and physical ex- amination, video-EEG monitoring, and case presentation at a weekly multidisciplinary epilepsy conference [21]. All patients were classified as nonsurgical candidates with drug-resistant epilepsy. This study was approved by the Institutional Review Board and was, therefore, Epilepsy & Behavior 31 (2014) 110–113 Abbreviations: VNS, vagus nerve stimulation; AED, antiepileptic drug. ⁎ Corresponding author. Fax: +1 813 259 0944. E-mail addresses: hwaseem@health.usf.edu (H. Waseem), sraffa@health.usf.edu (S.J. Raffa), sbenbadi@health.usf.edu (S.R. Benbadis), fvale@health.usf.edu (F.L. Vale). 1525-5050/$ – see front matter © 2013 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.yebeh.2013.12.002 Contents lists available at ScienceDirect Epilepsy & Behavior journal homepage: www.elsevier.com/locate/yebeh