Five-fold Gastrointestinal Electrical Stimulation With Electromyography-based Activity Analysis: Towards Multilocular Theranostic Intestinal Implants

Abstract

Background/Aims Motility disorders are common and may affect the entire gastrointestinal (GI) tract but current treatment is limited. Multilocular sensing of GI electrical activity and variable electrical stimulation (ES) is a promising option. The aim of our study is to investigate the effects of adjustable ES on poststimulatory spike activities in 5 GI segments. Methods Six acute porcine experiments were performed with direct ES by 4 ES parameter sets (30 seconds, 25 mA, 500 microseconds or 1000 microseconds, 30 Hz or 130 Hz) applied through subserosal electrodes in the stomach, duodenum, ileum, jejunum, and colon. Multi-channel electromyography of baseline and post-stimulatory GI electrical activity were recorded for 3 minutes with hook needle and hook-wire electrodes. Spike activities were algorithmically calculated, visualized in a heat map, and tested for significance by Poisson analysis. Results Post-stimulatory spike activities were markedly increased in the stomach (7 of 24 test results), duodenum (8 of 24), jejunum (23 of 24), ileum (18 of 24), and colon (5 of 24). ES parameter analysis revealed that 80.0% of the GI parts (all but duodenum) required a pulse width of 1000 microseconds, and 60.0% (all but jejunum and colon) required 130 Hz frequency for maximum spike activity. Five reaction patterns were distinguished, with 30.0% earlier responses (type I), 42.5% later or mixed type responses (type II, III, and X), and 27.5% non-significant responses (type 0). Conclusions Multilocular ES with variable ES parameters is feasible and may significantly modulate GI electrical activity. Automated electromyography analysis revealed complex reaction patterns in the 5 examined GI segments.

Robotic Setup Promises Consistent Effects of Multilocular Gastrointestinal Electrical Stimulation: First Results of a Porcine Study

“…The highest spike counts were found in the small bowel of both the conventional (jejunum) and robotic (ileum) setup. This result is consistent with our previous findings [15] and other studies. Romański et al [20]and Lammers et al [21]reported a higher number of Spm in the jejunum and ileum of pigs and dogs than in the human stomach and duodenum [22] and the porcine colon [23].…”

“…The pre- and poststimulatory EMG analysis, spike detection, and statistical analysis were based on our previous study [15]. Minute-by-minute EMG spike activity was analyzed using data at 5 locations from 5 experiments ( n = 25).…”

“…However, to date, few studies have investigated the effects of multilocular ES in multiple segments of the GI tract in animals or humans [12-14]. We recently described successful modulation of electrical activity in 5 GI segments using variable ES [15]. The conventional open surgical approach to multiple GI segments still involves a laparotomy with increased tissue trauma and may impair accuracy in the detection of modulating effects from ES.…”

The effect of colonic tissue electrical stimulation and celiac branch of the abdominal vagus nerve neuromodulation on colonic motility in anesthetized pigs

“…of colonic neuromodulation on healthy pigs has been the object of a limited number of reports so far. Most of these studies involve acute direct ES on anesthetized and cleansed descending colon [34][35][36][37] or cecum 38,39 using a broad range of stimulation parameters (5-130 Hz, 0.03-3 ms, 7-30 mA). These protocols induce local contractions (single point of stimulation), 35,39 propulsive contractions, [37][38][39] luminal content movement, 36,39 or acceleration of colonic transit in response to sequential stimulations.…”

“…Most of these studies involve acute direct ES on anesthetized and cleansed descending colon [34][35][36][37] or cecum 38,39 using a broad range of stimulation parameters (5-130 Hz, 0.03-3 ms, 7-30 mA). These protocols induce local contractions (single point of stimulation), 35,39 propulsive contractions, [37][38][39] luminal content movement, 36,39 or acceleration of colonic transit in response to sequential stimulations. 36,37,40 These data confirmed or expanded other preclinical studies performed in healthy [41][42][43][44] or constipation models 45,46 in rodents, cats, and dogs.…”