1. 2016;19;E1005-E1012Occipital Neuromodulation: A Surgical Technique with Reduced Complications
   Retrospective Analysis
   Matthew J. Pingree, MD, Bradford Landry, DO, MSPT, Gabriel L. Pagani-Estevez, MD, Thomas P. Pittelkow, DO, MPH, and Jason S Eldrige, MD.

BACKGROUND: Occipital neuromodulation is a promising treatment modality for refractory headache, but lead migration remains a frequent surgical complication.

OBJECTIVES: The primary objective was to identify surgical techniques that may minimize adverse events, particularly lead migration. We hypothesized that a surgical technique employing 2-point anchoring of stimulator leads designed to provide a tension-relief loop and the use of ultrasound for lead placement would decrease the complication rate.

STUDY DESIGN and SETTING: A retrospective analysis was performed through electronic medical record chart review in a tertiary referral center.

METHODS: Institutional Review Board (IRB) approval was obtained. Eighteen patients had a trial and subsequent permanent occipital nerve stimulator (ONS) implantation between 2004 and 2011 and were included. Adverse events were recorded and efficacy outcome variables analyzed for significance.

RESULTS: The cohort was a median (IQR) 45 (37 – 58) in age and 9 (50%) were women. Tension-relief loops placed via a 2-point anchoring technique and ultrasound use for occipital lead placement were evident in 16 (89%) and 13 (72%), respectively. There was one (6%) clinically insignificant lead position change, not definitively a lead migration, which could have been an artifact of fluoroscope positioning. Adverse events included one (6%) battery malfunction, one (6%) lead malfunction, and 2 (12%) post-implantation infections. Following ONS, there were significant reductions in numeric rating scale (NRS) pain scores from a median (IQR) of 9.5 (8.25 – 10) to 2.5 (1 – 4.75) (P < 0.0001), headache days per week from 7 (7 – 7) to 1.5 (0.375 – 1.75) (P = 0.0005), and the number of daily headache medication from 3 (2.25 – 4) to 2.5 (2 – 3.75) (P = 0.0112).

LIMITATIONS: Limitations include retrospective study design, investigator bias, and non-standardized intervals of headache burden assessment.

CONCLUSIONS: In ONS, utilization of a 2-point anchoring technique with a tension-relief loop may significantly minimize the risk of lead migration, based on the absence of definitive lead migration in our series. Ultrasound use may improve the anatomic accuracy of lead placement with the possibility of improved efficacy. ONS was associated with significantly decreased headache pain, frequency, and medication use.

Key words: Occipital neuromodulation, occipital nerve stimulation, surgical technique, lead migration, tension-relief loop