Sa2007 Colonic Motor Patterns in Patients With Chronic Constipation Assessed by High Resolution Manometry

Abstract

Colonic motor patterns, which might become biomarkers of colonic dysmotility in constipation, are still poorly defined in humans but have been clarified including the role of myogenic, neurogenic and interstitial cells of Cajal (ICC) control systems in the rat, mouse and guinea pig. The purpose of this study was to explore the characteristics of colonic motor patterns in 8 healthy volunteers and 22 patients with chronic constipation by high-resolutionmanometry (HRM). A 36-channel Unisensor solid-state probe, 1 cm spaced, was fixed at the transversedistal colon by colonoscopy for 6-8 hours manometry recording with Medkinetic acquisition software. After 60 min baseline recording, a yogurt meal (460 g, 1400 kJ) was given to observe the gastro-colonic reflex for 90 min, thereafter 2 mg prucalopride was given to evaluate short-term effects. Results: 1) Unique to HRM recordings were the clearly definable, distinguishable and quantifiable simultaneous and propulsive contractions which all had superimposed haustral contractions; distinct from any animal model. 2) In healthy volunteers, common motor patterns included simultaneous contractions (duration of 1-3 s, 40 100 mmHg, frequency 0.5-1.7 cpm), propulsive contractions including high amplitude propulsive contractions (HAPCs; 100-250 mmHg; figure), and stationary haustral contractions (30150 mmHg) that were often rhythmic at the ICC pacemaker frequency (3 cpm). The yogurt meal and 2 mg prucalopride promoted propulsive contractions, and decreased simultaneous contractions from 7 to 2 per 30 min recording. Eight HAPCs were observed in 3 cases, with propagating distances of 8-36 cm, amplitudes of 100-220 mmHg, velocity of 53 mm/s, several HAPCs were repetitive with intervals of 60-150 sec. HAPCs usually occurred without other patterns although it happened once in between 2 simultaneous contractions. 3) In patients with chronic constipation, simultaneous and retrograde-propagating contractions of low amplitude were the main patterns, no HAPCs were observed. Simultaneous contractions (duration 1-3 s, 30 mm Hg, frequency 0.4 -1.1 cpm) were significantly promoted by yogurt (from 5 to 16 episodes / 30 min). Retrograde contractions were increased after yogurt and prucalopride, with propagating distances of 8-21 cm, 10-60 mmHg, velocity of 61 mm/s and intervals of 60-150 sec. This did not occur in healthy volunteers. 4) Flatulence was associated with simultaneous contractions; yogurt increased the episodes of flatulence in both patients and healthy volunteers. In conclusion, rhythmic low amplitude simultaneous contractions and retrograde contractions, abundance of low amplitude rhythmic haustral contractions and failure to induce HAPCs characterized chronic constipation, suggestive of enhancement of local myogenic activity and dysfunctional neurogenic control systems of propulsion.