Technical note: Evaluation of tined endoscopically placed mucosal leads for temporary gastric neurostimulation

To compare larger diameter corkscrew-tined leads with previously described intracardiac pacing leads for temporary gastric neurostimulation in a canine model.

Two mongrel dogs underwent gastroscopy under general anesthesia, with endoscopic placement of two cardiac leads (1 mm tine diameter, 4 mm depth) placed sequentially in 1) transverse configuration in the distal antrum mucosa; 2) longitudinal (1 cm apart) configuration in gastric corpus. Stomach was then stimulated with maximal parameters to induce neutrally mediated contraction. Procedures were then repeated with larger leads (5 mm tine diameter, 8 mm length). Gastric contractions were measured with serosal strain transducers.

Leads were placed endoscopically without difficulty. Neither lead type punctured through to the serosa of the stomach. Neither cardiac nor larger leads were capable of eliciting any gastric contractile activity with endoscopic placement either in the transverse or longitudinal orientations.

While successful on the serosal side, both the cardiac leads and the larger alternative leads failed to produce stomach contraction when implanted mucosally. This may be due to the elastic nature of the mucosa, which was observed to twist around both types of leads significantly, hindering proper penetration into the muscularis.

These results suggest that the current concept of temporary gastric electrical neurostimulation via a mucosal approach must be reevaluated, as the procedure most likely does not accurately mimic electrical stimulation in the muscularis.