How I do it: surgical techniques for vagus nerve stimulation in pediatric drug-resistant epilepsy

Abstract

Background: Vagus nerve stimulation (VNS) is a neuromodulatory treatment for refractory epilepsy, involving electrical stimulation of the vagus nerve via a subcutaneously implanted pulse generator.

Method: We present a step-by-step description of the VNS implantation technique, incorporating tips and tricks from an epilepsy surgeon with over 20 years of experience (MB).

Conclusion: Proper patient selection, meticulous surgical technique, and comprehensive postoperative care, supported by educational resources such as surgical technique articles, videos, and simulators, are crucial for minimizing complications and optimizing patient outcomes.

Keywords: Drug-resistant epilepsy; Neurosurgery; Surgical technique; Vagus nerve stimulation.

Fig. 1

Patient Positioning and incisions: A The patient is positioned supine on the operating room table with the head on a donut pillow or a headrest, extended and turned, approximately, 30 degrees to the right. The neck is extended with a shoulder roll in order to ease the passage of the tunneling rod. B 2–3 cm transverse incision in a skin fold on the left side of the neck, located between the mastoid and the clavicle, extending to the medial border of the sternocleidomastoid muscle. C 2.5 to 3 cm-long incision following a skin crease line is performed, approximately 5 cm below the clavicle and 5 cm medially to the shoulder

Fig. 2

Neck incision and Vagus Nerve Dissection: A 2–3 cm transverse incision in a skin fold on the left side of the neck, located between the mastoid and the clavicle, extending to the medial border of the sternocleidomastoid muscle. B The subcutaneous dissection exposes the platysma, which can be divided following the directions of its fibers. C Muscle plane showing the omohyoid and other strap muscles inferiorly and medially, whereas the sternocleidomastoid is located laterally. D and G The carotid sheath is opened, showing the internal jugular vein laterally. E and H The carotid sheath is opened, showing the carotid artery medially. F and I The vagus nerve is located between the carotid artery medially and the internal jugular vein laterally

Fig. 3

Subcutaneous tunneling: A Manufacturer-supplied tunneling device, which includes an inner and an outer tunneling tube, and a bullet tip threaded onto the end of the inner tube. B Curvature of the tunneler to optimize the trajectory. C Tunneling from the neck incision towards the axillary incision. D The bullet tip is removed and the inner shaft is withdrawn, leaving the clear hollow sheath. E The free end of the electrode is inserted in the sheath and drawn, with the sheath, from the neck to the chest incision. F Electrode tunneled from the neck incision to the chest incision

Fig. 4

Simulator: A The electrode is positioned on the right side, passing underneath the nerve. B Once positioned beneath the nerve, forceps are used to reach the suture at the end of the helix, while the other forceps holds the opposite end of the suture on the right side of the nerve. Subsequently, controlled tension is applied to open the helices in the direction of the stimulator’s rotation, ensuring a precise fit on the nerve. C The central turn of the spiral is placed first. D By pulling the lower suture, the lower helix is placed around the nerve. E and F The upper helix is passed under the nerve, following the curvature of the electrode. G Electrode correctly positioned. H A common mistake is attempting to place the helices from the left side of the vagus nerve. Since the system is designed for right-handed surgeons, starting from the left side makes the placement very challenging, if not impossible. I Another common mistake: helices tangled with each other, making placement impossible. They should be stretched before placing them on the nerve

Fig. 5

Electrode placement: A The electrode is positioned on the right side, passing underneath the nerve. B Once positioned beneath the nerve, forceps are used to reach the suture at the end of the helix, while the other forceps holds the opposite end of the suture on the right side of the nerve. Subsequently, controlled tension is applied to open the helices in the direction of the stimulator’s rotation, ensuring a precise fit on the nerve. C and D In applying each electrode, the central part of the spiral must be positioned first, and then the upper and lower turns are wound around the nerve. The tethering (inferior) anchor is secured around the vagus nerve, and then the positive (middle helical contact) and the negative (upper helical contact) electrodes are positioned. E After the electrodes have been positioned on the nerve, it is necessary to make redundant loops so that movements of the neck do not dislodge the electrodes or put strain on the vagus nerve itself. F The electrode is secured by tacking nonabsorbable sutures to silicon holders at the deep cervical fascia