Immediate alterations in intestinal oxygen saturation and blood flow after massive small bowel resection as measured by photoacoustic microscopy
Purpose: 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. Conclusion: 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.
Additional Information© 2012 Elsevier Inc. Received 24 February 2012, Accepted 5 March 2012, Available online 15 June 2012. Wang laboratory research was supported by the National Institutes of Health Grants R01 EB000712, R01 EB008085, R01 CA134539, U54 CA136398, R01 EB010049, R01 CA157277, and 5P60 DK02057933. LVW has a financial interest in Microphotoacoustics, Inc, and Endra, Inc, which, however, did not support this work. Warner laboratory research was support by National Institutes of Health Grants R01 DK059288 (Warner) and T32 CA009621 (Rowland), and the St. Louis Children's Hospital Foundation - Children's Surgical Sciences Institute.
Accepted Version - nihms382246.pdf