Journal of Cytology & Histology

Functional Capillary Density for in Vivo Estimation of Intestinal Perfusion using Real-Time Confocal Endomicroscopy

Abstract

Luigi Schiraldi, Francesco Marchegiani, Michele Diana, Véronique Lindner, Eric Noll, Pierre Diemunsch and Jacques Marescaux

Background and aim: Confocal Laser Endomicroscopy (CLE) has been successfully used to appreciate microcirculation changes of the digestive mucosa. Our aim was to evaluate CLE scanning complemented by functional capillary density area (FCD-A) estimation to define the micro-vessel status in a reiterate, long-lasting porcine model of bowel ischemia.
Materials and methods: A laparotomy was performed in 4 pigs, and a segmental (3–4 cm) ischemia of the sigmoid colon was induced with vascular clamps. Ischemic and perfused regions were clinically defined. After an injection of 5 ml of sodium fluorescein 10% (Fluocyne, SERB, Paris, France), the Cellvizio™ confocal probe (Mauna Kea Technologies, Paris, France) was directly applied onto the mucosa’s surface through a full-thickness enterotomy. Both ischemic area (IA) and control region-perfused area (PA) – were scanned and video sequences were recorded.
Results: Confocal evaluation of the ischemic area revealed a different aspect of the mucosal tissue when compared to the normal perfused area. Statistically, FCD-A at the perfused area was significantly higher when compared to the ischemic area, irrespective of the time point. After 1 hour, FCD-A was (0.189 ± 0.094 vs. 0.365 ± 0.030; p=0.0001), after 2 hours (0.252 ± 0.056 vs. 0.389 ± 0.024; p<0.0001), after 3 hours (0.252 ± 0.050 vs. 0.353 ± 0.030; p=0.0001) and after 4 hours (0.262 ± 0.044 vs. 0.358 ± 0.019; p<0.0001), at ischemic and perfused areas respectively.
Conclusions: Confocal imaging allows real-time discrimination between perfused and ischemic areas of the bowel using morphological clues, while the functional capillary density area adds a quantitative measurement.