HP22P INTRA‐OPERATIVE MAPPING OF HUMAN GASTRIC SLOW WAVE ACTIVITY: INITIAL RESULTS

Abstract

Purpose: The stomach has an underlying slow wave activity that coordinates contractions. Human gastric slow wave activity is poorly understood, as existing descriptions rely on recordings from very few sites (typically ≤4). We aim to develop an improved description, in order to guide diagnostic and therapeutic strategies for dysmotility syndromes, such as post‐operative delays in gastric emptying.Methodology: Two novel electrode platforms were developed and validated for this study: a high‐resolution flexible printed circuit board (PCB) array (4 × 8 electrodes), and a laparoscopic device (2 × 2). Five patients have undergone intraoperative gastric mapping to date, using up to 6 tessellated PCBs (total of 192 electrodes; 96 cm2). Signals were recorded using the ActiveTwo System (Biosemi, Netherlands).Results: Slow wave frequencies were 2.85 ± 0.18 cycles per minute, with at least 3 distinct slow wave fronts being simultaneously active. Compared to corpus activity, antral activity was of greater amplitude (0.10 ± 0.03 mV vs. 0.04 ± 0.01 mV) and higher velocity (7.4 ± 1.1 mm s<συπ>−1<?συπ> vs. 2.8 ± 0.8 mm s<συπ>−1<?συπ>), with a sharp transition between regions. Isochronal mapping showed consistent aboral propagation. A relatively high amplitude / high velocity pacemaker area was localised high along the greater curvature.Conclusion: Initial mapping results suggest the need to revise existing descriptions of human gastric slow wave activity. The findings of multiple synchronous slow wave fronts, sharp regional variations in slow wave characteristics, and a high‐amplitude pacemaker zone need to be confirmed in a larger cohort of patients before the physiological, pathophysiological, diagnostic and therapeutic implications can be fully understood.