Publications

 

Monitoring gastric myoelectric activity after pancreaticoduodenectomy for diet "readiness".

Monica Dua, Anand Navalgund, Steve Axelrod, Lindsay Axelrod, Patrick J. Worth, Jeffrey A. Norton, George A. Poultsides, George Triadafilopoulos, and Brendan C. Visser.

American Journal of Physiology-Gastrointestinal and Liver Physiology 2018. Nov 1; 315(5):G743-G751

Postoperative delayed gastric emptying (DGE) is a frustrating complication of pancreaticoduodenectomy (PD). We studied whether monitoring of postoperative gastric motor activity using a novel wireless patch system can identify patients at risk for DGE. Patients (n = 81) were prospectively studied since 2016; 75 patients total were analyzed for this study. After PD, battery-operated wireless patches (G-Tech Medical) that acquire gastrointestinal myoelectrical signals are placed on the abdomen and transmit data by Bluetooth. Patients were divided into early and late groups by diet tolerance of 7 days [enhanced recovery after surgery (ERAS) goal]. Subgroup analysis was done of patients included after ERAS initiation. The early and late groups had 50 and 25 patients, respectively, with a length of stay (LOS) of 7 and 11 days (P < 0.05). Nasogastric insertion was required in 44% of the late group. Tolerance of food was noted by 6 versus 9 days in the early versus late group (P < 0.05) with higher cumulative gastric myoelectrical activity. Diminished gastric myoelectrical activity accurately identified delayed tolerance to regular diet in a logistical regression analysis [area under the curve (AUC): 0.81; 95% confidence interval (CI), 0.74–0.92]. The gastric myoelectrical activity also identified a delayed LOS status with an AUC of 0.75 (95% CI, 0.67–0.88). This stomach signal continued to be predictive in 90% of the ERAS cohort, despite earlier oral intake. Measurement of gastric activity after PD can distinguish patients with shorter or longer times to diet. This noninvasive technology provides data to identify patients at risk for DGE and may guide the timing of oral intake by gastric “readiness.”

NEW & NOTEWORTHY Limited clinical indicators exist after pancreaticoduodenectomy to allow prediction of delayed gastric emptying (DGE). This study introduces a novel, noninvasive, wireless patch system capable of accurately monitoring gastric myoelectric activity after surgery. This system can differentiate patients with longer or shorter times to a regular diet as well as provide objective data to identify patients at risk for DGE. This technology has the potential to individualize feeding regimens based on gastric activity patterns to improve outcomes.

Read Publication

Colon Myoelectric Activity Measured After Open Abdominal Surgery with a Noninvasive Wireless Patch System Predicts Time to First Flatus.

Anand Navalgund, Steve Axelrod, Lindsay Axelrod, Shyamali Singhal, Khoi Tran, Prithvi Legha, George Triadafilopoulos.

 Journal of Gastrointestinal Surgery 2018 Nov 2. doi: 10.1007/s11605-018-4030-4. [Epub ahead of print]

Passage of flatus after abdominal surgery signals resolution of physiological postoperative ileus (POI) and often, particularly after complex open surgeries, serves as the trigger to initiate oral feeding. To date, there is no objective tool that can predict time to flatus allowing for timely feeding and optimizing recovery. In an open, prospective study, we examine the use of a noninvasive wireless patch system that measures electrical activity from gastrointestinal smooth muscles in predicting time to first flatus.Eighteen patients who underwent open abdominal surgery at El Camino Hospital, Mountain View, CA, were consented and studied. Immediately following surgery, wireless patches were placed on the patients' anterior abdomen. Colonic frequency peaks in the spectra were identified in select time intervals and the area under the curve of each peak times its duration was summed to calculate cumulative myoelectrical activity. Patients with early flatus had stronger early colonic activity than patients with late flatus. At 36 h post-surgery, a linear fit of time to flatus vs cumulative colonic myoelectrical activity predicted first flatus as much as 5 days (± 22 h) before occurrence. In this open, prospective pilot study, noninvasive measurement of colon activity after open abdominal surgery was feasible and predictive of time to first flatus. Interventions such as feeding can potentially be optimized based on this prediction, potentially improving outcomes, decreasing length of stay, and lowering costs.

Read Publication

Conference Presentations

 

A New Motility Tool: High Concordance Between Internal Smartpill Pressure Recordings and Myoelectric Events Measured by External Wireless G-Tech Patches. Axelrod S, Navalgund A, Axelrod L and Triadafilopoulos G. Digestive Disease Week 2018, Washington DC 

Frequency Spectra from 72 Hour External Myoelectric Measurements of the Gut Demonstrate Strong Reproducibility as well as Sensitivity to Drug-Induced Stimulation. Axelrod L, Navalgund A, Axelrod S and Triadafilopoulos G. Digestive Disease Week 2018, Washington DC 

Colonic Myoelectrical Activity Measured Non-Invasively after Open Abdominal Surgery Predicts Time to First Flatus/Resolution of Postoperative Ileus. Navalgund A, Singhal S, Tran K, Legha P, Axelrod S, Axelrod L,  and Triadafilopoulos G. Digestive Disease Week 2018, Washington DC

Effect of GI stimulants on the surface-measured myoelectric signals of the stomach, small intestine and colon in a Crohn’s patient. Axelrod L, Navalgund A, Axelrod S and Triadafilopoulos G. Kenneth Rainin Foundation Innovation Symposium 2017. San Francisco, CA

Distinctive Electrical Signal Patterns Recorded at the Abdominal Surface in Subjects With Gastroparesis and Gastroesophageal Reflux Disease. Navalgund A, Kafai N, Axelrod S and Triadafilopoulos G. Digestive Disease Week 2016, San Diego, CA 

Spatial Localization of Surface-Measured Rhythmic Myoelectric Signals From Stomach, Small Intestine and ColonAxelrod L, Navalgund A, Axelrod S and Triadafilopoulos G, Digestive Disease Week 2016, San Diego, CA 

Signal Acquisition and Analysis of Surface-Measured Myoelectrical Signals of the Human GI tract. Triadafilopoulos G, Axelrod S, Navalgund A, Shah P, Devanaboyina U. ACG 2014 Annual Scientific Meeting and Postgraduate Course. Philadelphia, Pennsylvania Oct 2014

Signal Processing and Preliminary Clinical Utility of Surface-Measured Myoelectrical Signals of the Human GI tract. Triadafilopoulos G, Axelrod S, Navalgund A, Shah P, Devanaboyina U. ACG 2014 Annual Scientific Meeting and Postgraduate Course. Philadelphia, Pennsylvania Oct 2014

Early Clinical Utility of Surface-Measured Myoelectrical Signals of the Human GI tract. Triadafilopoulos G, Axelrod S, Navalgund A, Shah P, Devanaboyina U. ACG 2014 Annual Scientific Meeting and Postgraduate Course. Philadelphia, Pennsylvania Oct 2014

Contact Us

Fogarty Institute for Innovation

2490 Hospital Drive, Suite 310,

Mountain View, CA 94040

info@gtechmedical.com

G-Tech Medical

 © G-Tech Inc.  All rights reserved 

 Not approved for sale