Immediate alterations in intestinal oxygen saturation and blood flow after massive small bowel resection as measured by photoacoustic microscopy.
OBJECTIVE
Massive small bowel resection (SBR) results in villus angiogenesis and a critical adaptation response within the remnant bowel. Previous ex vivo studies of intestinal blood flow after SBR are conflicting. We sought to determine the effect of SBR on intestinal hemodynamics using photoacoustic microscopy, a noninvasive, label-free, high-resolution in vivo hybrid imaging modality.


METHODS
Photoacoustic microscopy was used to image the intestine microvascular system and measure blood flow and oxygen saturation (So(2)) of the terminal mesenteric arteriole and accompanying vein in C57BL6 mice (n = 7) before and immediately after a 50% proximal SBR. A P value of less than .05 was considered significant.


RESULTS
Before SBR, arterial and venous So(2) were similar. Immediately after SBR, the venous So(2) decreased with an increase in the oxygen extraction fraction. In addition, the arterial and venous blood flow significantly decreased.


CONCLUSIONS
Massive SBR results in an immediate reduction in intestinal blood flow and increase in tissue oxygen utilization. These physiologic changes are observed throughout the remnant small intestine. The contribution of these early hemodynamic alterations may contribute to the induction of villus angiogenesis and the pathogenesis of normal intestinal adaptation responses.
Division of Pediatric Surgery, St Louis Children's Hospital, Department of Surgery, Washington University School of Medicine, St Louis, MO 63110, USA.
Kathryn J
KJ
Rowland
Junjie
J
Yao
Lidai
L
Wang
Christopher R
CR
Erwin
Konstantin I
KI
Maslov
Lihong V
LV
Wang
Brad W
BW
Warner
D000222:Adaptation, Physiological; D000818:Animals; D001160:Arterioles; D007082:Ileum / Q000098:blood supply / Q000737:chemistry / Q000000981:diagnostic imaging / Q000601:surgery*; D008297:Male; D008642:Mesenteric Veins; D051379:Mice; D008810:Mice, Inbred C57BL; D008833:Microcirculation; D008853:Microscopy / Q000379:methods*; D055806:Microvessels / Q000000981:diagnostic imaging / Q000648:ultrastructure; D010092:Oximetry / Q000295:instrumentation / Q000379:methods*; D010100:Oxygen / Q000032:analysis* / Q000493:pharmacokinetics; D010108:Oxyhemoglobins / Q000032:analysis; D061088:Photoacoustic Techniques; D012778:Short Bowel Syndrome / Q000209:etiology / Q000503:physiopathology*; D013152:Splanchnic Circulation; D014463:Ultrasonography
D010108:Oxyhemoglobins; D010100:Oxygen