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Megaesophagus is one of the major manifestations of the chronic phase of Chagas disease. Its primary symptom is generally dysphagia due to disturbance in the lower esophageal sphincter. Microscopically, the affected organ presents denervation, which has been considered as consequence of an inflammatory process that begins at the acute phase and persists in the chronic phase. Inflammatory infiltrates are composed of lymphocytes, macrophages, natural killer cells, mast cells, and eosinophils. In this study, we evaluated the immunoreactivity of nerve growth factor (NGF), and of its receptor tropomyosin receptor kinase A (TrkA), molecules that are well known for having a relevant role in neuroimmune communication in the gastrointestinal tract. Esophageal samples obtained via autopsy or surgery procedures from six noninfected individuals, six infected individuals without megaesophagus, and six infected individuals with megaesophagus were analyzed. Infected individuals without megaesophagus presented increased numbers of NGF immunoreactive (IR) mast cells and increased areas of TrkA-IR epithelial cells and inner muscle cells. Infected individuals with megaesophagus showed increased numbers of NGF-IR eosinophils and mast cells, TrkA-IR eosinophils and mast cells, increased area of NGF-IR epithelial cells, and increased areas of TrkA-IR epithelials cells and inner muscle cells. The data presented here point to the participation of NGF and its TrkA receptor in the pathology of chagasic megaesophagus.

Achalasia is a motility disorder of the esophagus that might be secondary to a chronic Trypanosoma cruzi infection. Several studies have investigated esophageal achalasia in patients with Chagas disease (CD) in Latin America, but no related studies have been performed in Colombia. The goals of the present study were to determine the presence of anti- T. cruzi antibodies in patients with esophageal achalasia who visited a referral hospital in Bogotá, Colombia, and to detect the presence of the parasite and its discrete typing units (DTUs). This cross-sectional study was conducted in adult patients (18-65 years old) who were previously diagnosed with esophageal achalasia and from whom blood was drawn to assess antibodies against T. cruzi using four different serological tests. Trypanosoma cruzi DNA was detected by conventional polymerase chain reaction (cPCR) and quantitative polymerase chain reaction (qPCR). In total, 38 patients, with an average age of 46.6 years (standard deviation of ±16.2) and comprising 16 men and 22 women, were enrolled. Five (13.15%) patients were found to be positive for anti- T. cruzi antibodies by indirect immunofluorescence assay (IFA), and two patients who were negative according to IFA were reactive by both enzyme-linked immunosorbent assay and immunoblot (5.3%). Parasite DNA was detected in two of these seven patients by cPCR and in one of these by qPCR. The parasite DTU obtained was TcI. In summary, this study identified T. cruzi in Colombian patients with esophageal achalasia, indicating that digestive compromise could also be present in patients with chronic CD.

Small populations of Virginia opossum (Didelphis virginiana) in western Mexico are endangered by hunting and natural predators as well as by different kinds of diseases. After two serological analyses using Serodia® latex particle agglutination and indirect haemagglutination (IHA) tests, 35 (53.03%) of 66 collected opossums in two small towns in western Mexico were positive for the presence of Trypanosoma cruzi. Twenty-eight of the 35 seropositive opossums had pathological lesions: 11 had changes in only one organ, 13 in two organs, and four had pathological changes in three organs. Splenomegaly was the most common finding in the examined opossums, followed by hepatomegaly. These potentially fatal pathological changes could contribute to the scarcity of the opossum population, even leading to the extinction of this species in western Mexico.

Background: Idiopathic achalasia (IA) and Chagas' disease esophagopathy (CDE) share several similarities. The comparison between IA and CDE is important to evaluate whether treatment options and their results can be accepted universally. High-resolution manometry (HRM) has proved a better diagnostic tool compared to conventional manometry. This study aims to evaluate HRM classifications for idiopathic achalasia in patients with CDE., Methods: We studied 98 patients: 52 patients with CDE (52 % females, mean age, 57 ± 14 years) and 46 patients with IA (54 % females; mean age 48 ± 19 years). All patients underwent a HRM and barium esophagogram., Results: The Chicago classification was distributed in IA as Chicago I, 35 %; Chicago II, 63 %; and Chicago III, 2 %, and in CDE as Chicago I, 52 %; Chicago II, 48 %; and Chicago III, 0 % (p = 0.1, 0.1, and 0.5, respectively). All patients had the classic Rochester type. CDE patients had more pronounced degrees of esophageal dilatation (p < 0.002). The degree of esophageal dilatation did not correlate with Chicago classification (p = 0.08). In nine (9 %) patients, the HRM pattern changed during the test from Chicago I to II., Conclusion: Our results show that (a) HRM classifications for IA can be applied in patients with CDE and (b) HRM classifications did not correlate with the degree of esophageal dilatation. HRM classifications may reflect esophageal repletion and pressurization instead of muscular contraction. The correlation between manometric findings and treatment outcomes for CDE needs to be answered in the near future.

Chagasic megaoesophagus and megacolon are characterised by motor abnormalities related to enteric nervous system lesions and their development seems to be related to geographic distribution of distinct Trypanosoma cruzi subpopulations. Beagle dogs were infected with Y or Berenice-78 (Be-78) T. cruzi strains and necropsied during the acute or chronic phase of experimental disease for post mortem histopathological evaluation of the oesophagus and colon. Both strains infected the oesophagus and colon and caused an inflammatory response during the acute phase. In the chronic phase, inflammatory process was observed exclusively in the Be-78 infected animals, possibly due to a parasitism persistent only in this group. Myenteric denervation occurred during the acute phase of infection for both strains, but persisted chronically only in Be-78 infected animals. Glial cell involvement occurred earlier in animals infected with the Y strain, while animals infected with the Be-78 strain showed reduced glial fibrillary acidic protein immunoreactive area of enteric glial cells in the chronic phase. These results suggest that although both strains cause lesions in the digestive tract, the Y strain is associated with early control of the lesion, while the Be-78 strain results in progressive gut lesions in this model.

Introduction: Chagasic megaesophagus (CM) is the most common digestive manifestation of Chagas disease in Brazil, and the State of Goiás is one of the most affected regions. In recent decades, the Hospital das Clínicas (HC)/Universidade Federal de Goiás (UFG) has been a reference center for the study and treatment of CM. The objective of this study was to characterize the current epidemiological profile of patients with CM observed at the HC of the UFG from 1998 to 2010., Methods: In total, 939 patient records were analyzed, and age, gender, place of birth, serology, symptoms and radiological classification according to Rezende et al. were analyzed., Results: The median patient age was 55 years. Male patients were more (54%) prevalent than female patients. The prevalence of younger patients (less than 31 years of age) was 4.2%, but 82.1% of the younger patients were from State of Bahia. Patients older than 40 years were the majority (85.5%). The radiological groups were distributed as follows: Group I (35.9%), Group II (32.9%), Group III (17%) and Group IV (14.2%)., Conclusions: Compared with previous studies by the same group in 1975, 1994 and 1995, the number of younger patients decreased, and the frequency curve has shifted to older patients.

Laparoscopic Heller myotomy and fundoplication is considered today the treatment of choice for achalasia. The optimal treatment for end-stage achalasia with esophageal dilation is still controversial. This multicenter and retrospective study aims to evaluate the outcome of laparoscopic Heller myotomy in patients with a massively dilated esophagus. Eleven patients (mean age, 56 years; 6 men) with massively dilated esophagus (esophageal diameter greater than 10 cm) underwent a laparoscopic Heller myotomy and anterior fundoplication between 2000 and 2009 at three different institutions. Preoperative workup included upper endoscopy, esophagram, and esophageal manometry in all patients. Average follow-up was 31.5 months (range, 3 to 60 months). Two patients (18%) had severe dysphagia, four patients (36%) had mild and occasional dysphagia to solid food, and five patients (45%) were asymptomatic. All patients gained or kept body weight, except for the two patients with severe dysphagia. Of the two patients with severe dysphagia, one underwent esophageal dilatation and the other a laparoscopic esophagectomy. They are both doing well. Heller myotomy relieves dysphagia in the majority of patients even when the esophagus is massively dilated.

The authors report the case of a female infant with Group III (or Grade III) megaesophagus secondary to vector-borne Chagas disease, resulting in severe malnutrition that reversed after surgery (Heller technique). The infant was then treated with the antiparasitic drug benznidazole, and the infection was cured, as demonstrated serologically and parasitologically. After follow-up of several years without evidence of disease, with satisfactory weight and height development, the patient had her first child at age 23, in whom serological tests for Chagas disease yielded negative results. Thirty years after the initial examination, the patient's electrocardiogram, echocardiogram, and chest radiography remained normal.

Objective: To describe high resolution manometry features of a population of symptomatic patients with Chagas' disease esophagopathy (CDE)., Methods: Sixteen symptomatic dysphagic patients with CDE [mean age (54.81±13.43) years, 10 women] were included in this study. All patients underwent a high resolution manometry., Results: Mean lower esophageal sphincter (LES) extension was (3.02±1.17) cm with a mean basal pressure of (15.25±7.00) mmHg. Residual pressure was (14.31±9.19) mmHg. Aperistalsis was found in all 16 patients. Achalasia with minimal esophageal pressurization (type 1) was present in 25% of patients and achalasia with esophageal compression (type 2) in 75%, according to the Chicago Classification. Upper esophageal sphincter (UES) mean basal pressure was (97.96±54.22) mmHg with a residual pressure of (12.95±6.42) mmHg., Conclusions: Our results show that LES was hypotensive or normotensive in the majority of the patients. Impaired relaxation was found in a minority of our patients. Aperistalsis was seen in 100% of patients. UES had impaired relaxation in a significant number of patients. Further clinical study is needed to investigate whether manometric features can predict outcomes following the studies of idiopathic achalasia., (Copyright © 2012 Hainan Medical College. Published by Elsevier B.V. All rights reserved.)

Introduction: The prevalence of cholelithiasis in the general population ranges from 9 to 18%. This prevalence is known to be higher in the presence of parasympathetic nerve damage of the biliary tract either due to surgery (vagotomy) or neuronal destruction (Chagas disease). The objective of this study was to evaluate the association of cholelithiasis and chagasic or idiopathic megaesophagus., Methods: The ultrasound scans of 152 patients with megaesophagus submitted to cardiomyotomy and subtotal esophagectomy surgery were evaluated. The presence of cholelithiasis was compared between chagasic and idiopathic esophagopathy and ultrasound and clinical findings were correlated with age, sex and race., Results: A total of 152 cases of megaesophagus, including 137 with chagasic megaesophagus and 15 with idiopathic megaesophagus, were analyzed. The mean age was 56.7 years (45-67) in the 137 patients with chagasic megaesophagus and 35.6 years (27-44) in the 15 cases of idiopathic megaesophagus, with a significant difference between the two groups (p < 0.0001). The group with chagasic megaesophagus consisted of 59 (43%) women and 78 (56.9%) men, while the group with idiopathic megaesophagus consisted of 8 (53.3%) women and 7 (46.6%) men, showing no significant difference between the groups. Of the 137 patients with confirmed chagasic megaesophagus, 39 (28.4%) presented cholelithiasis versus one case (6.6%) in the 15 patients with idiopathic megaesophagus., Conclusions: The prevalence of cholelithiasis is high in patients with chagasic megaesophagus and preoperative ultrasound should be performed routinely in these patients in order to treat both conditions during the same surgical procedure.

Introduction: The aim of this study was to determine the contribution of preoperative gastric secretory and hormonal response, to the appearance of Barrett's esophagus in the esophageal stump following subtotal esophagectomy., Methods: Thirty-eight end-stage chagasic achalasia patients submitted to esophagectomy and cervical gastric pull-up were followed prospectively for a mean of 13.6 +/- 9.2 years. Gastric acid secretion, pepsinogen, and gastrin were measured preoperatively in 14 patients who have developed Barrett's esophagus (Group I), and the results were compared to 24 patients who did not develop Barrett's esophagus (Group II)., Results: In the group (I), the mean basal and stimulated preoperative gastric acid secretion was significantly higher than in the group II (basal: 1.52 vs. 1.01, p = 0.04; stimulated: 20.83 vs. 12.60, p = 0.01). Basal and stimulated preoperative pepsinogen were also increased at the Group I compared to Group II (Basal = 139.3 vs. 101.7, p = 0.02; stimulated = 186.0 vs. 156.5, p = 0.07. There was no difference in preoperative gastrin between the two groups. Gastritis was present during endoscopy in 57.1% of the Group I, while it was detected in 16.6% of the Group II, p = 0.014., Conclusions: Barrett's esophagus in the esophageal stump was associated to high preoperative levels of gastric acid secretion, serum pepsinogen, and also gastritis in the transposed stomach.

This study aimed to identify the main comorbidities in elderly chagasic patients treated in a reference service and identify possible associations between the clinical form of Chagas' disease and chronic diseases. Ninety patients aged 60 years-old or over were interviewed and their clinical diagnoses recorded. The study population profile was: women (55.6%); median age (67 years); married (51.1%); retired (73.3%); up to four years' education (64.4%); and earning less than two minimum wages (67.8%). The predominant forms of Chagas' disease were the cardiac (46.7%) and mixed forms (30%). There was a greater proportion of mild cardiac dysfunction (84.1%), frequently in association with megaesophagus. The mean number of concurrent diseases was 2.856 +/- 1.845, and 33% of the patients had four or more comorbidities. The most frequent were systemic arterial hypertension (56.7%), osteoporosis (23.3%), osteoarthritis (21.2%) and dyslipidemia (20%). Positive correlations were verified between sex and comorbidities and between age group and comorbidities.

Achalasia surgical treatment alters the esophagogastric junction anatomy (cardiomyotomy plus fundoplication or esophagectomy and gastric pull-up), thus favoring a certain degree of gastroesophageal reflux. Gastric secretory and hormonal functioning is not completely known in chagasic patients. The aim of this study was to evaluate the gastric secretory and hormonal response in patients with end-stage chagasic achalasia compared with normal subjects. Gastric secretion and hormonal response were assessed by estimation of gastric acid secretion (GAS) in basal condition and after pentagastrin stimulation, basal serum gastrin, and serum pepsinogen (SP) in basal condition and after betazole hydrochloride (Histalog; Eli Lilly and Company, Indianapolis, IN, USA) stimulation in 27 patients with chagasic achalasia. The results were then compared with those of 24 normal subjects. In the chagasic group, the mean basal and stimulated GAS were significantly lower than in the control group (basal: 1.277 vs. 3.13, P = 0.002; stimulated: 15.9 vs. 35.8, P = 0.0001). Chagasic patients' SG levels showed a significantly higher basal value than the control group (83.3 vs. 36.8, P = 0.0001). There was a significant increase of SP after stimulation compared with the basal levels in both chagasic and control groups. Although the chagasic patients' SP values were higher than the controls, this difference was not statistically significant, either in basal and stimulated conditions (basal: 122.0 vs. 108.9, stimulated 120 min: 177.1 vs. 158.9). In patients with chronic Chagas' disease (ChD), although autonomic denervation does not suppress the strength of the gastric mucosal cells' secretory response to stimulation, it reduces GAS (parietal cell) without, however, affecting SP production (chief cells). On the other hand, the gastrin-producing cells have continuously been stimulated by low GAS.

Trypanosoma cruzi presents a high degree of intraspecific variability, with possible implications for the pathogenesis of Chagas disease. The aim of this study was to evaluate T. cruzi kDNA minicircle gene signatures using the low-stringency single-specific-primer PCR technique in both peripheral blood and oesophageal mucosa from chronic chagasic patients, with or without megaesophagus, alone or in combination with cardiopathy and megacolon. It was not possible to identify a uniform pattern of shared bands between blood and oesophageal mucosa samples from individuals with the same clinical form or mixed forms, suggesting multiple T. cruzi infections with differential tissue tropism. Thus, the results indicate that there is an intense intraspecific variability in the hypervariable regions of T. cruzi kDNA, which has so far made it impossible to correlate the genetic profile of this structure with the clinical manifestations of Chagas disease.

Neuronal lesions have been considered the hallmark of chagasic megaesophagus, but the role of Trypanosoma cruzi and the participation of the inflammatory cells in this process are still debated. In the present study we counted neurons in the oesophagus from patients with and without megaesophagus and further examined these samples for the presence of parasite kDNA and cells with cytolytic potential (Natural Killer cells, cytotoxic lymphocytes and macrophages). The presence of parasite kDNA was demonstrated in 100% of cases with megaesophagus and in 60% of patients without megaesophagus. When analysed for the number of neurons, the patients without megaesophagus could be classified into 2 groups, as having normal or a decreased number of neurons. The former group did not show any inflammatory process, but interestingly, all patients without megaesophagus presenting decreased number of neurons also presented both parasite kDNA and inflammatory process in the organ. We further observed that the numbers of cytotoxic cells in the myenteric plexus region inversely correlate with the number of neurons. These data together strongly suggest that chronic lesions in chagasic megaesophagus might be a consequence of immune-mediated mechanisms, that last until the chronic phase of infection, and are dependent on the persistence of parasite in the host's tissue.

In order to characterize the demographic and clinical profile of patients with digestive manifestations of Chagas' disease, the medical records were reviewed of patients (n = 377) currently attended at Hospital das Clinicas da Faculdade de Medicina de Ribeirão Preto with positive serologic reaction for Chagas' disease and admitted from January 2002 to March 2003. Median age was 67 years and 210 (56%) were women. Megaesophagus and/or megacolon were present in 135 patients, 59% of these had cardiopathy. For 49% of patients with digestive disease, at least two medical prescriptions of medicines for the treatment of cardiovascular diseases were found. In 66 patients, chronic comorbidities were detected. The population with digestive manifestation of Chagas' disease referred to HCFMRP is mostly geriatric, with an elevated frequency of cardiopathy, which may indicate a high risk for surgical approach to the treatment of chagasic megaesophagus and megacolon.

Although Chagas' disease esophagopaty and idiopathic (primary) achalasia share several similarities, however, some differences between the two diseases have been noticed. To evaluate if treatment options and their results can be accepted universally, the authors review characteristics of both diseases in the international and Latin American literature. Neuronal denervation, sensitivity to gastrin, patient age, duration of symptoms, lower esophageal sphincter pressure, incidence of vigorous achalasia, and cancer risk are considered points of discrepancy between the maladies. Data with a high level of evidence base are scarce; however, differences between the diseases seem to exist, despite the fact that no influence on response to treatment was noticed.

We report the first case of digestive tract pathology (megaesophagus) determined by Trypanosoma cruzi infection in Santa Catarina State, southern Brazil. A 63-year-old female had presumptive clinical diagnosis of Chagas' disease, which was confirmed by imaging (endoscopy and esophagogram) and immunological methods. Further molecular diagnosis was carried out with esophagus and blood samples collected during corrective surgery. Polymerase chain reaction tested positive for Trypanosoma cruzi in both esophagus and buffy coat samples.

We have previously amplified Trypanosoma cruzi DNA by polymerase chain reaction (PCR) from the oesophagus of chagasic patients with megaoesophagus, whilst immunohistochemical analysis failed to detect T. cruzi antigen in the oesophagus of chagasic patients without megaoesophagus. During 2000-01, we tested for the presence of T. cruzi DNA in oesophageal tissue from 9 chronic chagasic patients without megaoesophagus and 5 were positive by PCR, which suggests that other factors, besides simply the presence of the parasite, should be considered in the understanding of the pathogenesis of megaoesophagus.

The persistence of Trypanosoma cruzi in tissue and blood of 52 patients in the digestive form of chronic Chagas disease was studied. These patients had chagasic megaesophagus and underwent corrective surgery. Parasitologic (xenodiagnosis, hemoculture, or both), histopathologic (hematoxylin and eosin, and peroxidase-anti-peroxidase staining), and molecular (polymerase chain reaction [PCR] followed by slot-blot hybridization) tests were used in the analysis. The presence of T. cruzi, its genomic fragments, or its antigens could be detected in 98% (51 of 52) of the patients. The parasite was randomly identified in 76.9% of esophageal tissues and in 90.4% by PCR and in 73.1% by parasitologic methods from the blood. Fifty percent (26 of 52) of tissue samples had inflammation, 80.8% of which was associated with the parasite. Trypanosoma cruzi was also identified unassociated with inflammatory alterations. Higher tissue parasitism and intense inflammatory processes were observed in esophageal tissue from patients with Grade IV megaesophagus. These data demonstrate that in the digestive form of Chagas' disease, particularly in cases of megaesophagus, T. cruzi is frequently found, both in blood and tissues and may contribute to the pathogenic mechanisms involved.

In this study, we isolated Trypanosoma cruzi from chronic Chagas heart disease and from megaesophagus patients. The parasite stock hSLU239 (heart disease) yielded clones h1 and h2, whereas stock mSEU142 (megaesophagus) yielded clones m1, m2, m3 and m4. The parasite growth kinetics, doubling time and differentiation in axenic liquid medium showed broad behavioral diversity. It was shown that a particular pattern of behavior for a parental stock could not necessarily be assigned for subsequent clones. This study indicates that i) each Chagas disease patient is infected with several T. cruzi populations; ii) clonal lines derived from patient samples may have different biological characteristics from the original isolate; and that iii) additional behavioral and/or molecular markers are required for further characterization of Trypanosoma cruzi stocks and clones derived from Chagas disease patients in order to identify correlations with pathology.

The authors report a case of schistosomiasis of uncommon location. A patient submitted to esophagectomy for Chagas' megaesophagus was found to have eggs of Schistosoma mansoni upon pathologic examination of the surgical specimen. The authors discuss the anatomopathological aspects of schistosomiasis, as well as its occurrence in other rare sites. To date, no references in literature have been found on the existence of esophageal schistosomiasis, and its association to Chagas' megaesophagus has never been described.

In the present study an attempt was made to analyse from a clinical viewpoint the descriptions in the book "Noticias do que he o achaque do bicho" by Miguel Dias Pimenta (1661-1715), which are considered by some authors to be the first reference to the chagasic megaesophagus and megacolon that appeared in history. In descriptions considered to refer megaesophagus, although dysphagia, the major symptom of this disease, is not recognized, typical manifestations of a irritating, inflammatory or ulcerative condition are identified, not affecting the esophagus but the stomach. In the description considered to refer to megacolon, the signs and symptoms suggest the diagnostic possibility of hemorrhoids and of the "achaque do bicho" itself, and do not recall the clinical picture of the chagasic megacolon in an absolute manner. On this basis, there is no reason to maintain the book "Noticias do que he o achaque do bicho" within the history of the digestive form of Chagas' disease.

Isoenzyme and RFLP analyses were carried on freshly isolated Trypanosoma cruzi stocks and subsequent clones derived from patients with chronic Chagas disease. The isoenzymes separated the parasite stocks and clones in two groups: The stock hSLU239 (group I), isolated from a heart disease patient, showed the zymodeme 3 (Z3) profile (M. A. Miles et al., 1977, Transactions of the Royal Society of Tropical Medicine and Hygiene 71, 217-225). The stock mSLU142 (group II), isolated from a digestive disease (megaesophagus) patient, showed the Z2 profile. The parasite clones m1, m2, m3, and m4, derived from mSLU142, and clones h1 and h2, derived from hSLU239, showed isoenzyme profiles similar to those of Z2 and ZA (Miles et al. 1977; J. A. Romanha, 1982, Thesis, Universidade Federal de Minas Gerais). Furthermore, the T. cruzi clones derived from the cardiac disease patient differed from those derived from the megacolon patient in 3 of the 13 enzymes analyzed. RFLP analysis showed polymorphism at the EcoRI and PstI restriction fragments of the DNA sequences coding the glycolytic enzymes ALD, GPI, GAPDH, and PYK and separated the T. cruzi stocks and clones in three groups: I, comprising the stock hSLU239 and clone m4, which was classified as homozygous CC, BB, AA, and AA for the ALD, GPI, PYK, and GAPDH genes, respectively; II, formed by the parasite stock mSLU142 and clones h1 and h2 (derived from hSLU239), which was classified as homozygous AA, AA, CC, and BB for ALD, GPI, PYK, and GAPDH genes, respectively . These findings show that the infection of each Chagas disease patient may be produced by genetically diverse mixed parasite populations.

A radiological study of the oesophagus of a cohort of patients was carried during a 13 year period in the municipality of Mambaí Goiás. Barium swallow findings were recorded on 70mm film using a portable machine. Of 731 patients examined 382 (52.3%) were seropositive for T. cruzi. The sexes were equally divided. The incidence of detectable megaoesophagus was 7.9% among the cohort and 14.2% in the seropositive individuals. Progression of the disease was noted during this longitudinal study in 21.7% of males and 16.6% of females.

The effect of Chagas' disease on the digestive tract is evaluated based on the experience acquired in the surgical management of 929 cases of megaesophagus: 807 in the nonadvanced state of the disease and 122 with dolichomegaesophagus. The 807 subjects with nonadvanced megaesophagus were submitted to wide esophagocardiomyectomy on the anterior esophagogastric junction combined with an antireflux valvuloplasty procedure. There was no mortality. On the other hand, dolichomegaesophagus was always resected, with an esophagogastroplasty through the esophageal bed. The index of mortality of the series was 4.1% (5/122) and the main postoperative complications were pleural effusion (22.1%) and fistula of the esophagogastric anastomosis (8.2%). Over the long term the patients adapted well to the operation and gained weight. For the treatment of the megacolon, an easier technique has been employed: resection of the dilated sigmoid colon and colorectal anastomosis just above the anorectal ring. In 30 patients, no leakages, infection or other major complications were seen. The patients, after 1 year of follow-up, had a normal bowel transit.

Systematized study was made in 56 esophagi of chronic chagasics (17 with and 39 without megas) aiming to: 1) to evaluate the esophageal caliber and thickness ranges; 2) analyse qualitative and quantitatively, the myenteric plexuses, trying to evaluate the relation of their lesions and the development of megaesophagus (ME); 3) study the lesions of the muscularis propria to verify if they contribute or not to the beginning of the process; 4) search for T. cruzi and its eventual relationship with the inflammation; 5) identify the principal mucosal alterations. It was confirmed that the severest lesions were found in the muscularis propria and in the plexures of Auerbach ganglia. In the former, the main alterations were myositis and fibrosis. The myentric plexuses showed inflammation and neuronal depopulation when compared with non-mega chagasic esophagi and even more when compared with the controls. On the other hand, there were normal caliber esophagi with severe denervation. It is possible that several factors may lead to the esophagopathy, especially to the ME. The search for T. cruzi was found positive in four out of eight esophagi with mega and in none of eight chagasic esophagi without mega. Mucosal and submucosal lesions were unremarkable and do not seem to be involved with the development of the process.

Patients diagnosed as having chronic chagasic esophagopathy were divided into three groups on the basis of radiologic findings: group I, no dilation; group II, moderate dilation, and group III, extensive dilation. Stasis esophagitis was more frequent in group III, with a significant increase in basal layer thickness when compared with groups I and II. The pathogenesis of basal layer hyperplasia may have been due to stasis of ingested food and to myenteric denervation of the viscera. This hyperplasia may be an intermediate condition explaining the higher frequency of cancer among patients with chagasic megaesophagus.

Two stocks of Trypanosoma cruzi isolated from patients with advanced megaoesophagus produced megastomach in chronically infected mice. The mice showed evidence of stomach dilatation and a delay in intestinal transit time. These findings are discussed in the light of the hypothesis that regional variations in T. cruzi determines mega formation in man.