Motility in the Roux-Y limb after distal gastrectomy: relation to the length of the limb and the afferent duodenojejunal segment--an experimental study.

Following gastrectomy, the longer is a Roux-Y limb constructed to restore digestive continuity the higher the frequency of postoperative symptoms. The aim of this experimental study was to test how the level of the jejunal transection and the length of the Roux limb affect the motility of the constructed limb and in particular the onset and the propagation of activity fronts (AFs). Three months after a distal Roux-en-Y gastrectomy, electromyographic tracings were recorded in six groups of rats grouped according to the level of the transection (20 or 40 cm from the pylorus) and the length of the limb (10, 20 or 30 cm). Animals in which a simple laparotomy or laparotomy + jejunal transection was performed, served as controls. During the interdigestive period, all animals had AFs in the limb which were independent from those recorded in the duodenum. In the limb, the mean time interval between two AFs was shorter (P < 0.01) and more irregular than in controls. An increase in limb length was associated with a lower incidence of completely propagated AFs (P < 0.05) and a higher incidence of irregularly propagated AFs (P < 0.01). When propagation of the AFs was analysed both in the limb and in the jejunum distal to the anastomosis, propagation abnormalities were more frequent. Below the gastrojejunal anastomosis, for an intestinal length of either 20 or 30 cm, the frequency of abnormal AFs was not different when this length was either only a limb or a limb with the 10 cm of distal jejunum below the jejuno-jejunal anastomosis. Interruption of AFs by a meal was irregular in the limb and more rarely observed in the 30-cm than in 10-cm limbs (P < 0.05). Interruption of AFs was shorter than in controls (P < 0.01). In the duodenum and the jejunum proximal to the limb, the interval between AFs was higher than in controls and in the Roux-Y limbs (P < 0.001). Intraluminal concentrations of bacterial strains were not different in the different types of limb while lactobacillus concentrations and pooled concentrations of bacteria were higher than in controls (P < 0.05). No relationship was found between the incidence of myoelectric abnormalities and intraluminal bacterial concentrations. Increasing the length of a Roux-Y limb resulted in more frequent disturbances in AFs in the limb but had no significant consequence on the overall rate of abnormal AFs in the jejunum distal to the transection. Motor response to food intake was also reduced. Motor changes were not related to intraluminal bacterial concentrations.