Abstracts

Rationale: Since vagal nerve stimulation was added into the surgical armamentarium for treatment of refractory epilepsy, infections have been reported in 1-6% of cases. However, our group has completed 100 consecutive cases without infection. Methods: All our patients are subjected to standardized presurgical evaluation; 7 or more Electroencephalogram, Video-Electroencephalogram, polisomnography, neuropsycological tests (patients able to cooperate) and MRI, as well as SPECT and PET in selected cases. VNS implantation in the left cervical vagus nerve is done under general anesthesia, with a one-day in hospital admittance. We routinely use antibiotic, cloramphenicol 1g/L(when contraindicated spreptomycin) in all irrigation solutions as well as prophylactic antibiotic (cephalothin in the younger age group and a fourth generation quinolone in adults), three doses on the surgical day continued for 10 days orally. Mean interval between implantation and start of stimulation, at minimal parameters, is fifteen days. Follow-up is carried out 4-6 weeks to adjust stimulation parameters, record seizure characteristics/frequency, on-demand use of magnet, and assess QoL. Results: All 100 systems were successfully implanted, 30 in the young age group (age range 2-20) and 70 in adults (range 21-54). Adverse effects included transitory cough and voice changes. Wounds healed unremarkably and no infections were registered. The use of antibiotic as well as a good surgical procedure with little incisions and minimal trauma to the tissues is the hallmark. Additionally we have had two battery replacements and one complete system exchange without infection. This series of patients responded to treatment very similarly to our previously reported series with a responder s rate of 72%, 58% among the generalized seizure group, and 84% in the partial seizure group. We have two patients who are seizure free, and 14 with over 90% improvement. The follow up on these cases was 14-108 months (mean 40) Conclusions: We believe that given good selection of candidates, a careful surgical procedure, use of prophylactic antibiotic and assurance of compliance to antibiotic postsurgical scheme, infection rate for VNS should be nil.