An Intraneural Electrode for Bioelectronic Medicines for Treatment of Hypertension.

OBJECTIVES: As the left vagus nerve (LVN) mediates a baroreflex blood pressure (BP) decrease, LVN stimulation (LVNS) could be a therapy for hypertension. Moreover, LVNS could elegantly be adjusted to the patient's actual BP and physical activity by using the neural information about BP and respiration extractable from LVN. However, unselective LVNS will trigger undesirable side-effects and therefore we here investigated the feasibility of using an intraneural electrode for extracting BP and respiration markers from the LVN and for selective LVNS.

MATERIALS AND METHODS: Experiments were performed on six anesthetized pigs from which the BP was recorded using arterial catheters and the respiratory cycles by recording the airway pressure. An electrode comprising four tripolar channels was inserted longitudinally in the LVN of the animals to extract BP and respiration markers from the LVN and for selective LVNS.

RESULTS: BP-related and respiratory-related neural profiles (BPnPs and RnPs, respectively) were derived from at least two electrode channels in all pigs. The BPnPs accurately resembled the BP waves and the RnPs accurately resembled the respiratory cycles, which suggests that those profiles could serve as BP and respiration markers, respectively. The BP was decreased by intraneural LVNS in all pigs and in four of those pigs such an effect was induced without major cardiac changes through a channel-selective stimulation.

CONCLUSION: This study shows that it is feasible to extract BP and respiratory markers from the LVN with the tested intraneural electrode and suggests that this electrode could also be used for selective LVNS.