98 - Freie Mitteilung
17. Mai 2019, 14:15 - 15:45, Kursaal Arena, 5. OG
Simultaneous computer-assisted assessment of mucosal and serosal perfusion in a model of segmental colonic ischemia
B. Seeliger, P. Mascagni, F. Longo, M. Barberio, A. Lapergola, D. Mutter, A. Klymchenko, V. Agnus, J. Marescaux, M. Diana, Presenter: B. Seeliger (Strasbourg/FR)
Adequate perfusion is crucial for optimal anastomotic healing. Fluorescence-based enhanced reality (FLER) is used to quantify fluorescence signal dynamics and to superimpose a virtual perfusion cartogram onto real-time laparoscopic images. In current surgical practice, fluorescence-guided perfusion estimation is obtained from the serosal side. The aim of this experimental study was to quantify potential differences (due to a different ischemia response) in mucosal and serosal perfusion levels in an ischemic colon segment.
An ischemic colon segment was created in 12 pigs. Simultaneous quantitative serosal and mucosal fluorescence imaging was obtained via intravenous indocyanine green injection (0.2mg/kg), using 2 near-infrared camera systems, and computer-assisted FLER analysis. Lactate levels were measured in capillary blood of the colonic wall at 7 regions of interest (ROIs) as determined by FLER analysis: the ischemic zone (I), the threshold of a 50% signal intensity variation over time proximally and distally at the mucosal and serosal side (P50M, P50S, D50M, D50S) and the proximal and distal vascularized areas (PV, DV).
Perfusion level differences between mucosa and serosa were clearly identified using the perfusion cartographies. The mean ischemic zone as measured (mm) at the mucosal side was significantly larger than the serosal one (56.3±21.3 vs. 40.8±14.9, p=0.001), with a mean difference of 1.5±1.2cm. Mean lactate levels (mmol/L) in the ischemic area (3.8±2.1), were significantly higher than those in P50M (2.2±2.7, p=0.0007), P50S (2.6±2.6, p=0.01), D50M (2.4±2, p=0.002), D50S (2.8±1.9, p=0.003), and vascularized zones (PV 1.75±2.2, p=0.0001; DV 1.7±2.2, p<0.0001). Due to the symmetrical distribution of ischemia, the pooled analysis of proximal (n=24) and distal (n=24) lactate levels showed significantly higher levels at the serosal side (2.7±2.2 vs. 2.3±2.3, p=0.02).
In an experimental model of acute ischemia, the simultaneous image acquisition of both colonic wall sides showed larger ischemic mucosal zones as compared to serosal ones. The potential clinical relevance of these results calls for an assessment of perfusion from the mucosal side or for performing a larger resection when basing the analysis on serosal perfusion. Further studies are required to predict the optimal resection margin and anastomotic site in colonic resections.