br Material and methods br The inclusion
2. Material and methods
The inclusion criteria of the study were as follows: 1) histological evidence of gastric or colorectal carcinoma, 2) lack of neoplastic ca-chexia, 3) at least 18 years of age, 4) discontinuation of all medications with potential effect on gastric motility and autonomic system activity 3 days prior to the study, 5) Eastern Cooperative Oncology Group (ECOG) performance status of 1 or 0, and 6) written informed consent.
The exclusion criteria included cardiovascular disorders, neurolo-gical disorders, gastrointestinal disorders other than carcinoma, dia-betes mellitus, obesity (Body Mass Index > 30 kg/m2), tobacco smoking, alcohol abuse, intake of medications with an established ef-fect on gastric myoelectric measurements, previous history of abdom-inal surgery other than anticancer treatment, pregnancy and chronic Advances in Medical Sciences 64 (2019) 44–53
Basic characteristics of colon cancer patients (group A).
abdominoperineal amputation of the rectum – 1
abdominoperineal amputation of the rectum,
sigmoidectomy with metastasectomy – 2 (6.7%)
abdominoperineal amputation of the rectum and
hemicolectomy and anterior resection of the rectum
anterior resection of the rectum and sigmoidectomy
anterior resection of the rectum and metastasectomy
hyperthermic intraperitoneal chemotherapy (HIPEC)
disorders that 3XFLAG may affect gastrointestinal and/or autonomic function. All subjects were asked to fast for at least 12 h before the in-vestigation and to withdraw all medications with established effects on autonomic function and gastrointestinal motility for 3 days preceding
None of the study participants showed abnormalities in complete blood count parameters and results of biochemical tests for kidney and liver function. Performance status of all subjects was 0 or 1. The vast majority of them (75%) had radical surgical treatment. Four patients with colon cancer had surgical treatment due to intestinal obstruction. Detailed characteristics of the study subjects are presented in Tables 1, 2 and 3 .
2.1. Assessment of gastric myoelectric activity
The research was performed on patients reporting to the laboratory in the morning, after a 12-h overnight fast. 30-min EGG recordings of gastric myoelectric activity under basal conditions were obtained after an overnight fast and 1 h after a standard meal (Nutridrink, Nutricia, 300 kcal/300 ml). EGG was conducted with a four-channel electro-gastrography Polygraf NET (Medtronic, USA) described earlier by Simonian et al. , Wang et al.  and Krusiec-Świdergoł et al. . After completing a standard preparatory procedure, involving, if ne-cessary, shaving of the skin, and careful skin abrasion with the use of Every paste, and placing a set of six Ag/AgCl electrodes - designed primarily for long-term electrocardiographic monitoring - on the ab-dominal skin over the stomach (Fig. 1) [1,27]. Four of them were active electrodes: the third active (3) electrode was fixed in the midline, half way between the xiphoid process and the umbilicus (which is a stan-dard position for a single-channel electrogastrography), the fourth (4) electrode was attached 4–6 cm to the right – horizontally in line with electrode 3, whereas the second (2) and the first (1) electrode were placed with a 4–6 cm interval on a line leading up from electrode 3 at a 45° angle towards the left costal margin. The reference electrode (Ref) was placed at the interception of a horizontal line passing through electrode 1 and a vertical line stretching from electrode 3. The
Basic characteristics of rectal cancer patients (group B).
abdominoperineal amputation of the rectum - 10
proctocolectomy and partial resection of the
TEM (transendoscopic microsurgery) with
anterior resection of the rectum with
surgical treatment metastasectomy – 1 (3.3%)
transcatheter arterial chemoembolization (TACE)
Basic characteristics of gastric cancer patients (group C).
surgical treatment gastroenterostomy – 1 (5%)
chemotherapy + targeted therapy (trastuzumab) – 4
hyperthermic intraperitoneal chemotherapy
grounding electrode (Gnd) was placed on the left costal margin on a horizontal line starting from electrode 3. Finally, a motion sensor was taped to the abdominal skin. The electrodes were connected to a Medtronic POLYGRAM NET EGG 311,224 system (Medtronic Func-tional Diagnostics A/S). Fig. 2
2.1.1. Multichannel electrogastrogram analysis
The primary signal was sampled at 105 Hz, filtered through a 15 cpm low pass filter, and subsequently down-sampled to 1 Hz and stored in a database on a desktop computer. Next, the high-pass filter with the cutoff frequency set to 1.8 cpm was applied to the signal prior to the EGG-analysis (Polygram NetTM Reference Manual) by a researcher blinded to the experimental conditions linked to a particular data set. At first, a visual inspection of the tracings was performed to identify