RADIOLOGICAL STUDY OF MEGACOLON IN TRYPANOSOMA CRUZI INFECTED RATS.

BACKGROUND: Researches on Chagas disease still use several animals and rats, due to size and susceptibility were preferred by many authors. AIM: To develop an experimental model of megacolon in rats inoculated with the strain Y of Trypanosoma cruzi. METHODS: Thirty male Wistar rats were distributed in three groups inoculated with different inoculants: Group A: 600000, Group B: 1000000 and Group C: 1500000 blood trypomastigotes of T. cruzi. Animals were sedated intramuscularly at zero inoculation time (T0) and 60 days after inoculation (T60), to perform the barium enema in order to evaluate the dilatation of the different segments of colon in a comparative study of the measurements obtained, using a digital caliper. Evidence of infection was performed by blood smear collected from the animal's tail 18 days after inoculation with observation of blood forms. RESULTS: Comparing the intestinal diameter of the inoculated animals with 60,0000 trypomastigotes in the T0 of infection with T60 days after the inoculation, significant dilatation was observed between the proximal, medial and distal segments (p<0.01), indicating the establishment of the megacolon model. In addition, comparing intestinal diameter between the different segments, with in the T0 of infection and the T60 after inoculation, significant alterations were observed (p<0.05). CONCLUSION: The proposed model was possible for in vivo studies of alterations due to infection by T. cruzi and functional alterations of the colon. In addition, the changes manifested in the colon are not directly proportional to the size of the inoculum, but to the time of infection that the animals were submitted, since the animals inoculated with 60,0000 blood forms were the ones which presented the most significant alterations.

Radiological study of megacolon in trypanosoma cruzi infected rats / Estudo radiológico de megacólon em ratos infectados por trypanosoma cruzi

ABSTRACT Background: Researches on Chagas disease still use several animals and rats, due to size and susceptibility were preferred by many authors. Aim: To develop an experimental model of megacolon in rats inoculated with the strain Y of Trypanosoma cruzi. Methods: Thirty male Wistar rats were distributed in three groups inoculated with different inoculants: Group A: 600000, Group B: 1000000 and Group C: 1500000 blood trypomastigotes of T. cruzi. Animals were sedated intramuscularly at zero inoculation time (T0) and 60 days after inoculation (T60), to perform the barium enema in order to evaluate the dilatation of the different segments of colon in a comparative study of the measurements obtained, using a digital caliper. Evidence of infection was performed by blood smear collected from the animal's tail 18 days after inoculation with observation of blood forms. Results: Comparing the intestinal diameter of the inoculated animals with 60,0000 trypomastigotes in the T0 of infection with T60 days after the inoculation, significant dilatation was observed between the proximal, medial and distal segments (p<0.01), indicating the establishment of the megacolon model. In addition, comparing intestinal diameter between the different segments, with in the T0 of infection and the T60 after inoculation, significant alterations were observed (p<0.05). Conclusion: The proposed model was possible for in vivo studies of alterations due to infection by T. cruzi and functional alterations of the colon. In addition, the changes manifested in the colon are not directly proportional to the size of the inoculum, but to the time of infection that the animals were submitted, since the animals inoculated with 60,0000 blood forms were the ones which presented the most significant alterations.

RESUMO Racional: Pesquisas para doença de Chagas ainda utilizam diversos animais e o rato por seu tamanho e sua suscetibilidade foi o preferido por muitos pesquisadores. Objetivo: Desenvolver um modelo experimental de megacólon em ratos inoculados com a cepa Y de Trypanosoma cruzi. Métodos: Utilizou-se 30 ratos, machos, distribuídos em três grupos inoculados com diferentes inóculos: Grupo A: 600000, Grupo B: 1000000 e Grupo C: 1500000 tripomastigotas sanguíneos da cepa Y de T. cruzi. Os animais foram sedados via intramuscular no tempo zero de inoculação (T0) e aos 60 dias após a inoculação (T60) para realização de enema opaco para avaliação da dilatação dos diferentes segmentos do cólon em estudo comparativo das medidas obtidas, com o auxílio de um paquímetro digital. A comprovação da infecção foi realizada com esfregaço de sangue coletado a partir da cauda do animal 18 dias após a inoculação com observação das formas sanguíneas. Resultados: Ao comparar o diâmetro intestinal dos animais inoculados com 60.0000 formas tripomastigotas no T0 de infecção com T60 dias após a inoculação, observou-se dilatação significativa entre os segmentos proximal, medial e distal (p<0,01), indicando o estabelecimento do modelo de megacólon. Além disso, ao comparar o diâmetro intestinal entre os diferentes segmentos, dentro do T0 de infecção e do T60 após a inoculação, observou-se alterações significantes (p<0,05). Conclusões: O modelo proposto mostrou-se factível para estudos in vivo das alterações decorrentes da infecção pelo T. cruzi e alterações funcionais do cólon. Além disso, as alterações manifestadas no cólon não são diretamente proporcionais ao tamanho do inóculo, mas sim ao tempo de infecção que os animais foram submetidos, visto que os inoculados com 600000 formas sanguíneas foram as que mais apresentaram alterações significantes.

Long-term follow up of abdominal rectosigmoidectomy with posterior end-to-side stapled anastomosis for Chagas megacolon.

AIM: Chagas' disease is an endemic parasitosis found in Latin America. The disease affects different organs, such as heart, oesophagus, colon and rectum. Megacolon is the most frequent long-term complication, caused by damage to the myoenteric and submucous plexus, ultimately leading to a functional barrier to the faeces. Patients with severe constipation are managed surgically. The study aimed to analyse the 10-year minimum functional outcome after rectosigmoidectomy with posterior end-to-side anastomosis (RPESA). METHOD: A total of 21 of 46 patients were available for follow up. Patients underwent clinical, radiological and manometric evaluation, and the results were compared with preoperative parameters. RESULTS: Of the 21 patients evaluated, 81% (17) were female, with a mean age of 60.6 years. Good function was achieved in all patients, with significant improvement in defaecatory frequency (P < 0.0001), usage of enemas (P < 0.0001) and patient satisfaction. Barium enema also showed resolution of the colonic and rectal dilatation in 19 cases evaluated postoperatively. CONCLUSION: Minimal 10-year follow up of RPESA showed excellent functional results, with no recurrence of constipation.

[Radiological study on megacolon cases in an endemic area for Chagas disease]. / Estudo radiológico do megacólon em área endêmica de doença de Chagas.

INTRODUCTION: A radiological study on the colon of patients from an endemic Chagas disease zone was conducted using the simplified opaque enema technique of Ximenes et al. METHODS: The study involved 291 individuals with a mean age of 48.8 ± 12.5 years-old, of whom 222 were seropositive for Chagas disease. Anteroposterior, posteroanterior and left lateral view radiographs were analyzed by visual inspection and measurement of the largest rectal and sigmoid diameters. RESULTS: From the visual inspection, megacolon was diagnosed in 14 (6.3%) Chagas disease patients. The mean diameter of the rectal ampulla among the Chagas patients was 6.3 ± 1.0 cm, similar to the measurement in non-Chagas individuals: 6.2 ± 1.0 cm (p= 0.391). The mean sigmoid loop diameter in the Chagas patients was 5 ± 1.6 cm, which was larger than among the non-Chagas individuals: 4.4 ± 0.8 cm (p= 0.001). CONCLUSIONS: excluding the evident and probable megacolon cases, the Chagas disease population continued to present a significantly larger mean sigmoid diameter than that observed among non-Chagas individuals (p= 0.003).

Estudo radiológico do megacólon em área endêmica de doença de Chagas / Radiological study on megacolon cases in an endemic area for Chagas disease

INTRODUÇÃO: Foi realizado estudo radiológico do cólon em pacientes de zona endêmica da doença de Chagas usando-se a técnica do enema opaco simplificado de Ximenes e cols. MÉTODOS: Participaram 291 pacientes, com idade media de 48,8 (±12,5) anos, sendo 222 soropositivos para doença de Chagas. Fizeram radiografias na posição ântero-posterior, póstero-anterior e perfil lateral esquerdo, que foram analisadas por inspeção visual e medida do maior diâmetro em centímetros do reto e sigmoide. RESULTADOS: À inspeção visual, foi possível diagnosticar megacólon em 14 (6,3 por cento) pacientes chagásicos. A média do diâmetro da ampola retal dos chagásicos 6,3 (±1,0)cm foi semelhante a dos não-chagásicos 6,2 (±1,0)cm (p=0,391) e o diâmetro médio da alça sigmoide dos chagásicos 5 (±1,6)cm foi maior que o dos não chagásicos 4,4 (±0,8 )cm, (p=0,001). CONCLUSÕES: Excluindo-se os casos de megacólon evidente e de provável megacólon, a população chagásica continuou com o diâmetro médio do sigmoide significantemente maior (p=0,003) que a não chagásica.

INTRODUCTION: A radiological study on the colon of patients from an endemic Chagas disease zone was conducted using the simplified opaque enema technique of Ximenes et al. METHODS: The study involved 291 individuals with a mean age of 48.8(±12.5) years-old, of whom 222 were seropositive for Chagas disease. Anteroposterior, posteroanterior and left lateral view radiographs were analyzed by visual inspection and measurement of the largest rectal and sigmoid diameters. RESULTS: From the visual inspection, megacolon was diagnosed in 14 (6.3 percent) Chagas disease patients. The mean diameter of the rectal ampulla among the Chagas patients was 6.3 (±1.0)cm, similar to the measurement in non-Chagas individuals: 6.2 (±1.0) cm (p= 0.391). The mean sigmoid loop diameter in the Chagas patients was 5 (±1.6)cm, which was larger than among the non-Chagas individuals: 4.4 (±0.8)cm (p= 0.001). CONCLUSIONS: excluding the evident and probable megacolon cases, the Chagas disease population continued to present a significantly larger mean sigmoid diameter than that observed among non-Chagas individuals (p= 0.003).

Surgical treatment of Chagasic megacolon by abdominal rectosigmoidectomy with immediate posterior end-to-side stapling (Habr-Gama technique).

PURPOSE: Various techniques have been used in the surgical treatment of Chagasic megacolon, including sympathectomy, sphincterotomy, anterior abdominal resection with high or low anastomosis, pull-through procedures, and Duhamel technique. However, results have not been consistently satisfactory, with reportedly high morbidity and mortality rates. The purpose of this study was to assess the technique and results of anterior rectosigmoidectomy with immediate posterior colorectal end-to-side stapled anastomosis for the treatment of Chagasic megacolon. METHODS: A prospective, noncontrolled study between 1989 and 2000 analyzed 49 patients with Chagasic megacolon. Preoperative barium enema confirmed Chagasic megacolon in all patients and preoperative anorectal manometry in 33 patients (67 percent). Rectal stump closure was undertaken by surgical stapling in 41 patients (84 percent); mechanical colorectal anastomosis was accomplished with a circular stapler in all patients. RESULTS: Symptoms of intestinal constipation ranged from 6 months to 40 years, Chagas' serology was positive in 98 percent of patients, 41 percent used bowel enemas for evacuation, and 71 percent had a history of fecaloma. The overall postoperative complication rate was 20 percent. Surgical complications occurred in 18 percent, 2 percent had nonsurgical complications, and there was no mortality. Postoperative barium enema was performed in 82 percent of cases, confirming the absence of disease. Postoperative anorectal manometry demonstrated normal resting pressure and rectal capacity; the inhibitory reflex remained absent and rectal sensitivity was increased. Ninety-three percent of patients were followed for more than 48 months, and all patients reported daily stool elimination without recurrence of constipation. CONCLUSIONS: The current study indicates that our technique is effective for surgical treatment of patients with Chagasic megacolon.

Chagasic megacolon associated with colon cancer.

Two cases of chagasic megacolon associated with colon cancer are reported. This is the first communication with complete clinical details of this association. Our two cases presented tumors (adenocarcinomas) in a nondilated segment of the transverse colon. The associated tumor lesions were diagnosed by a barium enema. Both patients had a typical clinical epidemiology and history of chagasic megacolon.