title: Relationship between altered small intestinal motility and absorption after abdominal aortic aneurysm repair.
abstract: OBJECTIVE
  Small intestinal (SI) motor patterns are often disrupted after major non-gastrointestinal (non-GI) surgery, but the impact on luminal flow and nutrient absorption is unclear. This study examines interactions between SI motility, flow and absorption in the first 3 days after surgical repair of abdominal aortic aneurysm (AAA).
  
  
  METHODS
  Concurrent assessments of SI motility (manometry), flow (impedancometry) and lipid (¹³C-triolein) and glucose [plasma 3-O-methyl-glucose (3-OMG)] absorption were performed in 13 patients (12 male; 77 ± 2 years) on days 1 and 3 post surgery during 3-h intra-duodenal nutrient infusion (Ensure® with 200 μl ¹³C-triolein, 3 g 3-OMG). Data, presented as mean ± standard error of mean (SEM), are compared with 10 healthy volunteers (9 male; 57 ± 4 years).
  
  
  RESULTS
  On day 1 post surgery, there were more motility bursts, fewer impedance events and reduced absorption of ¹³C-triolein [cumulative percent dose recovery (cPDR) 22.9 ± 2.4% versus 31.2 ± 4.2%; P < 0.001] and 3-OMG, compared with health. By day 3, total number of bursts and flow events were similar between groups, with fewer retrograde and more antegrade flow episodes. ¹³C-triolein absorption remained low in patients on day 3 (26.7 ± 2.2%, P < 0.05), correlating positively with total number of flow events (r = 0.49; P < 0.01), but negatively with prolonged events (r = -0.37; P = 0.03). In patients, 3-OMG absorption increased from day 1 to 3 to a level comparable to health.
  
  
  CONCLUSIONS
  Whilst disruption in SI motility and flow (impedance) events was associated with reduced absorption of both lipid and carbohydrate, lipid malabsorption was more prolonged. This may reflect inadequate mixing of chyme from altered motility, so varying the nutrient composition of enteral feed may improve absorption in these patients.
authors.affiliation: Departments of Gastroenterology and Hepatology, Royal Adelaide Hospital, North Terrace, Adelaide, SA, 5000, Australia. quoc.nguyen@health.sa.gov.au
authors.forename: Nam Q
authors.initials: NQ
authors.lastname: Nguyen
authors.forename: Laura K
authors.initials: LK
authors.lastname: Besanko
authors.forename: Carly M
authors.initials: CM
authors.lastname: Burgstad
authors.forename: Jim
authors.initials: J
authors.lastname: Burnett
authors.forename: Brendan
authors.initials: B
authors.lastname: Stanley
authors.forename: Ross
authors.initials: R
authors.lastname: Butler
authors.forename: Richard H
authors.initials: RH
authors.lastname: Holloway
authors.forename: Robert J L
authors.initials: RJ
authors.lastname: Fraser
mesh_terms: D000368:Aged; D017544:Aortic Aneurysm, Abdominal / Q000601:surgery*; D005260:Female; D005769:Gastrointestinal Motility / Q000502:physiology*; D006801:Humans; D007408:Intestinal Absorption; D007421:Intestine, Small / Q000503:physiopathology*; D008297:Male; D008365:Manometry; D008991:Monitoring, Physiologic / Q000379:methods; D011183:Postoperative Complications / Q000503:physiopathology*