Microendoscopic view ×150 showing serosal surface and underlying capillary network. No methylene blue stain was used. The larger calibre serosal capillaries are easier to visualise, in real time actual cells and flow is visible within the lumen of the vessels. The procedure may be undertaken intraoperatively (during graft setting and before tissue coverage) and on sentinel graft islands postoperatively to assess perfusion. Again time gated image analysis can be performed to provide quantifiable data on blood flow and perfusion with colorimetric analysis possible to assess state of oxygen saturation.