Clinical treatment of the digestive form of Chagas disease.

The digestive form of Chagas disease, first individualized by JM Rezende (1959 Rev Goiana Med 5: 193), represents, together with the cardiac form, the most important manifestation of the chronic phase of Trypanosoma cruzi infection. The anatomopathologic basis of the digestive form of Chagas disease is denervation of the complex network of intramural neurons (M Amorin & A Correia Neto 1932 An Fac Med São Paulo 8: 101, E Etzel 1934 An Fac Med São Paulo 10: 631, F Köberle 1968 Adv Parasitol 6: 63), today known as enteric nervous system. This fact was demonstrated not only by the detailed histological studies cited above, but also by in vivo denervation tests involving the administration of drugs with a cholinergic action (RA Godoy & CB Vieira 1961 Acta Physiol Lat Amer 11: 107, CB Vieira & R A Godoy 1963 Rev Goiana Med 8: 21, UG Meneghelli 1968 Rev Goiana Med 14: 61). The nervous system plays a fundamental role in the regulation of the motor functions of the digestive tube. Consequently, its destruction causes disorders in the motility of the affected organ. The esophagus and sigmoid colon are preferentially affected by denervation. From a physiological viewpoint, motor dysfunction is characterized, since the pre-ectasic phases, by the presence of lower sphincter achalasia and by the loss of peristaltic organization of the movements of the esophageal body, and by reduction of the response to physiological stimuli and basal hypomotility in the colon. The esophageal abnormalities may not arise simultaneously during the course of the disease (UG Meneghelli 1996 XXXIV Cong Brasil Gastroenterol, Goiânia). The symptomatic clinical manifestations of the digestive form of Chagas disease are expressed as dysphagia in the presence of esophagopathy and as intestinal constipation in the presence of colonic disease. The most notable structural consequences of the denervation caused by these pathologies are megaesophagus and megacolon, respectively. The treatment of esophagopathy and of colonic disease can be clinical, surgical and, in the case of esophagopathy, may also involve procedures for cardia dilatation. Whatever the treatment used, it will necessarily be symptomatic since the basic lesion of the disease is neuronal destruction, which is irreversible.