Long-term effects of jejunoileal autotransplantation on myoelectrical activity in canine small intestine.

We studied the longitudinal effects of autotransplantation on the motor function of the jejunoileum. By performing the autotransplantation procedure in a manner similar to that employed for allotransplantation, we sought to examine the long-term effects of both extrinsic denervation and the operative procedure itself on small intestinal motor function. Although initially disrupted, interdigestive myoelectrical activity demonstrated progressive organization: 88% of migrating myoelectrical complexes in animals studied between 12 and 20 months following autotransplantation demonstrated each phase of the complex in normal sequence. Longitudinal studies of several parameters of myoelectrical activity provided further evidence of progressive organization and entrainment of motor functions within the denervated intestine. Several abnormal myoelectrical patterns were observed within the autotransplanted segment, however, and coordination of either slow wave or phase III activity with the proximal innervated intestine did not recover with time. The major component of the myoelectrical response to feeding was permanently impaired with a delayed onset and shortened duration of the fed response. We conclude that the extrinsically denervated intestine recovers the ability to generate and organize all phases of the MMC but demonstrates permanent impairment of the major motor response to food. However, anoxic and cooling damage to enteric nerves and muscle, incurred during the autotransplantation procedure, may explain the persistence of abnormal motor patterns and impaired myoelectrical conduction and could play an important role, additional to that of extrinsic denervation, in the long-term motor function of the allotransplanted intestine.