The mucosal blood flow in pelvic pouches in man. A methodologic study of fluorescein flowmetry

Fluorescein flowmetry implies the measurement of capillary blood flow, expressed as an index between the maximum fluorescence after the first circulatory passage of sodium fluorescein (NaF) and the rise time, defined as the time interval between ten and 90 percent of the maximum fluorescence. A mathematic model based on fluorescein flowmetry was deduced to distinguish a mucosal and muscular blood flow in an intact (unopened) intestine during surgery in man. The hypothesis was that if, at a certain point in time, there is a fixed relationship between the seromuscular fluorescence and the mucosal maximum fluorescence, obtained during the first circulatory passage of NaF, and if the rise times were equal, then a mucosal blood flow could be calculated based on the seromuscular fluorescence. The model was tested in intestinal anastomoses on 16 patients. A fixed relationship between the numeric value of the mucosal maximum fluorescence and the seromuscular fluorescence was found. After five minutes, the ratio was 1:1 and the correlation coefficient at its highest (0.97). It was also found that the rise times were practically identical (r = 0.92). The validity of the model was then tested by comparing it with fluorescein flowmetry, and the correlation coefficient was 0.85. The model was therefore accepted and named indirect mucosal fluorescein flowmetry. Indirect mucosal fluorescein flowmetry was applied to measure blood flow in pelvic pouches in 14 patients, and fluorescein flowmetry in the ileoanal anastomoses in eight patients. The mucosal blood flow in the reservoir, compared with the normal intestine, was reduced to 58 percent if the ileocolic artery or distal branches of the mesenteric artery were ligated, and to 88 percent if the vessels were left intact (P less than 0.05). In the ileoanal anastomosis the mucosal blood flow was reduced to 23 percent compared with the normal intestine (P less than 0.01). The results suggest that stretching and compressing the mesentery might be critical for circulation in the ileoanal anastomoses.