EFFERENT LIMB MYONEURAL AND LUMINAL CONTINUITY AND POSTGASTRECTOMY GASTRIC-EMPTYING

Delayed gastric emptying and altered upper gut transit or both are com mon following Roux-en-Y gastrojejunostomy and are thought to be due to altered efferent limb transit secondary to isolation of the Roux limb from the duodenal pacemaker. We postulated that preservation of myone ural continuity of the Roux limb with the duodenal pacemaker would enh ance solid gastric emptying, while division of the afferent limb of a Billroth II gastrojejunostomy (B-II), isolating the efferent jejunal l imb from the duodenal pacemaker, would slow gastric emptying. Solid ga stric emptying was measured in 14 dogs, who then underwent gastric vag otomy and antrectomy. Eight animals were reconstructed with a Roux-en- Y gastrojejunostomy, preserving myoneural but not luminal continuity o f the Roux limb with the afferent limb via a muscularis bridge, while six dogs underwent standard B-II gastrojejunostomy. Serosal electrodes were placed on the afferent and efferent jejunal limbs. Gastric empty ing was restudied, with fed and fasted myoelectric recordings. The bri dge was then divided to create a standard Roux, while the afferent lim b was transected and reanastomosed just proximal to the gastrojejunost omy in the B-II dogs to isolate the efferent limb from the duodenal pa cemaker, with repeat studies. Bridge dogs had delayed solid gastric em ptying compared to their preoperative state, despite normal efferent l imb motility. Gastric emptying was not further altered by division of the bridge, despite altered efferent limb motility, including a decrea sed migrating myoelectric complex (MMC) cycle length (62 +/- 1 vs 128 +/- 18 min, P < 0.001), slow wave frequency (SWF) (14.1 +/- 0.6 vs 17. 6 +/- 0.6 cpm, P < 0.01), postptrandial suppression of MMCs (60 +/- 18 vs 303 +/- 28 min, P < 0.01), and an inverted SWF gradient, indicatin g ectopic pacemakers. Solid gastric emptying was unchanged after stand ard B-II compared to the preoperative state, even following transectio n and reanastomosis of the afferent limb. Solid gastric emptying was f aster in the latter group than in Roux animals, despite similar effere nt limb motility. We conclude that myoneural continuity of the efferen t limb of a gastrojejunostomy with the duodenal pacemaker is less impo rtant than luminal continuity of the afferent and efferent limbs in de termining postgastrectomy solid gastric emptying. (C) 1995 Academic Pr ess, Inc.