Abstracts

Rationale: Implantation of the Aspire 106 VNS generator requires a preoperative cardiac evaluation. This is cumbersome, time consuming and requires donated hospital resources and personnel. We designed a implant technique to eliminate the need for preoperative evaluation as presently required for the placement of the Aspire SR pulse generator, allow for minimum sensitivity settings and the most accurate detection of heart rate change Methods: Intra-operatively 3 or 5 lead EKG (telemetry) button electrode pads are positioned with the leftarm (black) pad is placed over the anticipated VNS lead site in the neck and the left leg (red) pad is placed over the anticipated location of the pulse generator (typically 3 cm lateral to the mid-sternum in the region between where V2 and V3 pads would be in normal 12 lead EKG). Tracing from this lead is observed to ensure the amplitude is greater than 0.4 mV. Neck dissection for VNS lead placement is done in the usual fashion, while the pulse generator is placed in a subcutaneous pocket at the target location viaan anterior axillary incision. Anatomic localization is also described and places the pulse generator between the sternal border and the midclavicular line. Results: Using the EKG method a cohort of 56 patients, 55 (98.2%) achieved appropriate heartbeat detection at a sensitivity of one, while one (1.8%) was set at two. Using the anatomic method, all 34 patients (100%) achieved appropriate heartbeat detection at a sensitivity of 1. Both methods use a more efficient method than described by VNS pre-surgical evaluation. Conclusions: Both EKG based localization and anatomic localization methods provide a reliable, efficient,and durable way of placing the AspireSR pulse generator with excellent heartbeat detection. Funding: none