A Single-Center Experience with the NeuroPace RNS System: A Review of Techniques and Potential Problems.
BACKGROUND
The clinical results for the RNS System (NeuroPace, Mountain View, California, USA) closed-loop responsive neurostimulator for the treatment of medically intractable partial-onset seizures have been encouraging. The University of Southern California (USC) Neurorestoration Center and the Keck Hospital of USC have become the world's first institutions to implant an RNS System post U.S. Food and Drug Administration (FDA) approval. As one of the study centers, we review our experience with our group of patients who have been implanted with the RNS System.


METHODS
A total of 40 surgeries by a single surgeon were performed on 10 patients (7 male and 3 female) with an average age of 39.2 years (24-66 years) and were followed for an average of 45 months (30-54 months). The average age at seizure onset was 14 years (birth-37 years) with an average of 4.7 (3-12) failed antiepileptic drugs. We reviewed the patients' charts for complications from the surgeries including infections requiring surgical intervention, hematomas, hardware failures, and death.


RESULTS
Of the 40 surgeries, there were 10 initial implantations of the neurostimulator and leads, 24 neurostimulator replacements for expected end of neurostimulator service, 2 incision and drainage procedures (I & Ds) for soft tissue infection followed by 1 explantation and 1 reimplantation (same patient), and 2 revisions because of one lead that was damaged at the exit point between the skull and a titanium mesh and the second lead that was damaged at an acute bend over the skull (same patient). Eight of the patients had no complications and underwent an average of 2.7 neurostimulator replacements over 7 consecutive years to date. Each patient underwent routine postoperative computed tomography imaging of the brain, and none had any intracranial hematomas or misplaced leads requiring revision surgery. Finally, there were no deaths in our patient population.


CONCLUSIONS
Our experience with the NeuroPace RNS System over an average follow-up of 45 months suggests that the surgery and device are safe when placed by an experienced surgeon. Although there were no clinically significant hematomas or patient deaths, we did have 1 patient each with infection and lead damage at the point of exit from the skull. We compare the results of this study with other neuromodulation procedures for epilepsy to evaluate the safety and complications associated with the RNS System. Our initial experience suggests that the RNS System can be readily incorporated into an active epilepsy surgical center.
Department of Neurosurgery, University of Southern California, Keck School of Medicine, Los Angeles, California, USA. Electronic address: brianlee@usc.edu.
Brian
B
Lee
Department of Neurosurgery, University of Southern California, Keck School of Medicine, Los Angeles, California, USA.
Muhammad N
MN
Zubair
Department of Neurosurgery, University of Southern California, Keck School of Medicine, Los Angeles, California, USA.
Yvette D
YD
Marquez
Department of Neurosurgery, University of Southern California, Keck School of Medicine, Los Angeles, California, USA.
David M
DM
Lee
Department of Neurology, University of Southern California, Keck School of Medicine, Los Angeles, California, USA.
Laura A
LA
Kalayjian
Department of Neurology, University of Southern California, Keck School of Medicine, Los Angeles, California, USA.
Christianne N
CN
Heck
Department of Neurosurgery, University of Southern California, Keck School of Medicine, Los Angeles, California, USA; Department of Neurology, University of Southern California, Keck School of Medicine, Los Angeles, California, USA.
Charles Y
CY
Liu
D000328:Adult; D000368:Aged; D004351:Drug Resistance; D004599:Electric Stimulation Therapy / Q000009:adverse effects / Q000295:instrumentation* / Q000379:methods; D004567:Electrodes, Implanted; D004828:Epilepsies, Partial / Q000628:therapy*; D004868:Equipment Failure; D005260:Female; D005500:Follow-Up Studies; D007839:Functional Laterality; D006801:Humans; D008297:Male; D008875:Middle Aged; D019635:Neurosurgical Procedures; D012189:Retrospective Studies; D013238:Stereotaxic Techniques; D013530:Surgical Wound Infection / Q000628:therapy; D016896:Treatment Outcome; D055815:Young Adult
Epilepsy; NeuroPace; Neuromodulation; RNS System; Safety