Complete or partial obstruction of the duodenum by the superior mesenteric artery (SMA) is a rare cause of bowel obstruction. SMA syndrome results from the compression of the 3rd part of the duodenum between the superior mesenteric artery and the abdominal aorta. Causes include anatomical variation in the superior mesenteric artery, trauma, burns, surgeries, malignancy, and rapid weight loss. Diagnosis of SMA syndrome in patients may be difficult, as the clinical findings often resemble other forms of small bowel obstructions. This syndrome was first described in the literature by Carl Freiherr von Rokitansky in 1861. Subsequently, David Wilke provided a comprehensive description of the disease in a series of 75 patients. There has been skepticism about the existence of SMA syndrome due to scant literature reports and non-specific symptomatology. However, modern cross-sectional imaging has confirmed the existence of this rare syndrome. Here we present the case of a 50-year-old female with longstanding symptoms of gastrointestinal discomfort, weight loss, nausea, and vomiting. She underwent an exhaustive gastrointestinal workup until a diagnosis of SMA syndrome was made. We elected to proceed with a minimally invasive three-port laparoscopic, trans-mesenteric side-to-side duodenojejunostomy. The patient was discharged on postoperative day one after tolerating a regular diet. On one month follow-up, our patient reported improvement in symptoms with no postprandial pain or nausea and normal bowel movements. In conclusion, we report a case of superior mesenteric artery syndrome in a patient with recurrent abdominal pain and nausea. CT scan has the highest sensitivity for the diagnosis of SMA syndrome, findings suggestive of the diagnosis include an abnormal aortomesenteric angle and distance. While supplemental tube feeds and gastric drainage may resolve the condition without the need for surgery, this often takes many weeks to months to be effective. Minimally invasive surgical bypass is an attractive option because of the rapidity of symptom resolution, lack of need for long-term invasive tubes, short inpatient length of stay, and high success rate.

Yes / Video capsule endoscopy (VCE) is a revolutionary technology for the early diagnosis of gastric disorders. However, owing to the high redundancy and subtle manifestation of anomalies among thousands of frames, the manual construal of VCE videos requires considerable patience, focus, and time. The automatic analysis of these videos using computational methods is a challenge as the capsule is untamed in motion and captures frames inaptly. Several machine learning (ML) methods, including recent deep convolutional neural networks approaches, have been adopted after evaluating their potential of improving the VCE analysis. However, the clinical impact of these methods is yet to be investigated. This survey aimed to highlight the gaps between existing ML-based research methodologies and clinically significant rules recently established by gastroenterologists based on VCE. A framework for interpreting raw frames into contextually relevant frame-level findings and subsequently merging these findings with meta-data to obtain a disease-level diagnosis was formulated. Frame-level findings can be more intelligible for discriminative learning when organized in a taxonomical hierarchy. The proposed taxonomical hierarchy, which is formulated based on pathological and visual similarities, may yield better classification metrics by setting inference classes at a higher level than training classes. Mapping from the frame level to the disease level was structured in the form of a graph based on clinical relevance inspired by the recent international consensus developed by domain experts. Furthermore, existing methods for VCE summarization, classification, segmentation, detection, and localization were critically evaluated and compared based on aspects deemed significant by clinicians. Numerous studies pertain to single anomaly detection instead of a pragmatic approach in a clinical setting. The challenges and opportunities associated with VCE analysis were delineated. A focus on maximizing the discriminative power of features corresponding to various subtle lesions and anomalies may help cope with the diverse and mimicking nature of different VCE frames. Large multicenter datasets must be created to cope with data sparsity, bias, and class imbalance. Explainability, reliability, traceability, and transparency are important for an ML-based diagnostics system in a VCE. Existing ethical and legal bindings narrow the scope of possibilities where ML can potentially be leveraged in healthcare. Despite these limitations, ML based video capsule endoscopy will revolutionize clinical practice, aiding clinicians in rapid and accurate diagnosis.

Small bowel cancer (SBC) is the malignancy with the highest standardized incidence ratio in Lynch syndrome (LS) patients. Of all SBCs, about 50% are duodenal cancers (DCs), therefore being accessible by esophago-gastro-duodenoscopy (EGD) for surveillance. We asked whether early detection of DC is possible for LS patients undergoing surveillance by EGD and if surveillance should be limited to specific subgroups. Data for LS patients with DC were retrieved from the registry of the German Consortium for Familial Intestinal Cancer. Patients undergoing active surveillance by EGDs (surveillance group) were compared to those who did not (nonsurveillance group) regarding tumor stage at diagnosis. Union for International Cancer Control stages I-IIA were defined as early stage disease and IIB-IV as advanced stage disease. Statistical analysis was performed using Fisher's exact test. Among 2015 patients with pathogenic variants in any mismatch-repair-gene, 47 patients with 49 DCs were identified. In 10% of cases, patients were under 35 years at diagnosis; family and personal tumor history did not correlate with DC diagnosis. Pathogenic germline variants in MSH6, PMS2 or EPCAM were present in 10% of patients. Statistical analysis could be performed on 13 DC patients in the surveillance group and 14 in the nonsurveillance group. Early detection was possible for 71% of patients in the surveillance group and 29% of patients in the nonsurveillance group (P = .021). Early detection of DC by EGD in LS patients is feasible regardless of family history, mutational status and should start no later than 25 years of age.

Objetivo: Avaliar a influência da localização da enterocolite necrosante neonatal na mortalidade de recém-nascidos (RN) submetidos à laparotomia exploradora. Métodos: Estudo de coorte prospectiva de 141 recém-nascidos com ECN submetidos consecutivamente à laparotomia exploradora no período de novembro de 1991 a dezembro de 2005. Foram avaliados dados epidemiológicos, localização e extensão da doença, crescimento intra-uterino e o número de óbitos no período de 60 dias após a cirurgia. Resultados: Setenta e quatro (52,5%) crianças eram do sexo masculino, com peso médio de nascimento de 1.589 ± 665 gramas, com idade gestacional média de 33,6 ± 2,9 semanas. Prematuridade ocorreu em 84,4% (119/141) dos RN. Cinqüenta e sete (40,4%) eram pequenos para a idade gestacional. Óbito ocorreu em 68 crianças (48,2%). Na análise bivariada, observou-se que o comprometimento do jejuno-íleo foi associado com alta mortalidade (20 óbitos - 76,9%; OR = 20; intervalo de confiança de 95% = 4,6 - 96,3; p < 0,001) e que a doença no jejuno estava associada à maior extensão da ECN. Entretanto, no modelo de regressão logística múltipla com controle individual de cada variável, a doença no jejuno-íleo (OR = 0,61; intervalo de confiança de 95% = 0,06 - 6,14; p = 0,68) e no intestino grosso (OR = 2,91; intervalo de confiança de 95% = 0,81 - 10,50; p = 0,10) não foram consideradas fatores de risco para o óbito. Conclusões: Em análise adequada, com controle isolado de cada variável estudada, a mortalidade foi independente da localização da ECN no intestino delgado ou no intestino grosso. Porém, a localização da doença no jejuno foi um marcador de maior extensão da ECN e, conseqüentemente, de pior prognóstico. Extensão difusa da doença e recém-nascidos PIG foram os mais importantes fatores de risco de ocorrência de óbito nesses recém-nascidos submetidos à cirurgia. / Aim of the study: To evaluate the effect of disease site on the mortality rate of newborns with necrotizing enterocolitis (NEC) undergoing exploratory laparotomy. Methods: Prospective cohort of 141 consecutive newborns with NEC who underwent laparotomy from November 1991 to December 2005. The study variables included epidemiologic data, disease site and extent, intrauterine growth, and number of deaths in the 60 days after operation. The protocol was approved by the institution’s Research Ethics Committee. Main results: Seventy-four (52.5%) infants were male. Mean birth weight was 1,589 ± 665 g, and mean gestational age was 33.6 ± 2.9 weeks. One-hundred and nineteen (84.4%) newborns were premature. Small for gestational age was observed in 57 (40.4%). Sixty-eight (48.2%) infants died. Bivariate analysis revealed that involvement of the jejunum and ileum was associated with high mortality rates (20 deaths, 76.9%; OR = 20; 95% 95% CI = 4.6 – 96.3; p < 0.001), and that involvement of the jejunum was associated with greater disease extent. After controlling for individual variables, logistic regression showed that the mortality associated with jejunum and ileum involvement (OR = 0.61; 95% CI = 0.06 - 6.14; p = 0.68) did not differ from that associated with large bowel involvement (OR = 2.91; 95% CI = 0.81 – 10.50; p = 0.10); however, jejunum involvement remained significantly associated with disease extent. Conclusions: NEC-related mortality in newborns undergoing laparotomy was not influenced by disease site (small or large bowel). However, jejunum involvement was a marker of greater disease extent and therefore of poor prognosis. Diffuse disease extent and small for gestational age were the most important markers of risk of death in NEC newborns submitted to surgery.

Objetivo: Avaliar a influência da localização da enterocolite necrosante neonatal na mortalidade de recém-nascidos (RN) submetidos à laparotomia exploradora. Métodos: Estudo de coorte prospectiva de 141 recém-nascidos com ECN submetidos consecutivamente à laparotomia exploradora no período de novembro de 1991 a dezembro de 2005. Foram avaliados dados epidemiológicos, localização e extensão da doença, crescimento intra-uterino e o número de óbitos no período de 60 dias após a cirurgia. Resultados: Setenta e quatro (52,5%) crianças eram do sexo masculino, com peso médio de nascimento de 1.589 ± 665 gramas, com idade gestacional média de 33,6 ± 2,9 semanas. Prematuridade ocorreu em 84,4% (119/141) dos RN. Cinqüenta e sete (40,4%) eram pequenos para a idade gestacional. Óbito ocorreu em 68 crianças (48,2%). Na análise bivariada, observou-se que o comprometimento do jejuno-íleo foi associado com alta mortalidade (20 óbitos - 76,9%; OR = 20; intervalo de confiança de 95% = 4,6 - 96,3; p < 0,001) e que a doença no jejuno estava associada à maior extensão da ECN. Entretanto, no modelo de regressão logística múltipla com controle individual de cada variável, a doença no jejuno-íleo (OR = 0,61; intervalo de confiança de 95% = 0,06 - 6,14; p = 0,68) e no intestino grosso (OR = 2,91; intervalo de confiança de 95% = 0,81 - 10,50; p = 0,10) não foram consideradas fatores de risco para o óbito. Conclusões: Em análise adequada, com controle isolado de cada variável estudada, a mortalidade foi independente da localização da ECN no intestino delgado ou no intestino grosso. Porém, a localização da doença no jejuno foi um marcador de maior extensão da ECN e, conseqüentemente, de pior prognóstico. Extensão difusa da doença e recém-nascidos PIG foram os mais importantes fatores de risco de ocorrência de óbito nesses recém-nascidos submetidos à cirurgia. / Aim of the study: To evaluate the effect of disease site on the mortality rate of newborns with necrotizing enterocolitis (NEC) undergoing exploratory laparotomy. Methods: Prospective cohort of 141 consecutive newborns with NEC who underwent laparotomy from November 1991 to December 2005. The study variables included epidemiologic data, disease site and extent, intrauterine growth, and number of deaths in the 60 days after operation. The protocol was approved by the institution’s Research Ethics Committee. Main results: Seventy-four (52.5%) infants were male. Mean birth weight was 1,589 ± 665 g, and mean gestational age was 33.6 ± 2.9 weeks. One-hundred and nineteen (84.4%) newborns were premature. Small for gestational age was observed in 57 (40.4%). Sixty-eight (48.2%) infants died. Bivariate analysis revealed that involvement of the jejunum and ileum was associated with high mortality rates (20 deaths, 76.9%; OR = 20; 95% 95% CI = 4.6 – 96.3; p < 0.001), and that involvement of the jejunum was associated with greater disease extent. After controlling for individual variables, logistic regression showed that the mortality associated with jejunum and ileum involvement (OR = 0.61; 95% CI = 0.06 - 6.14; p = 0.68) did not differ from that associated with large bowel involvement (OR = 2.91; 95% CI = 0.81 – 10.50; p = 0.10); however, jejunum involvement remained significantly associated with disease extent. Conclusions: NEC-related mortality in newborns undergoing laparotomy was not influenced by disease site (small or large bowel). However, jejunum involvement was a marker of greater disease extent and therefore of poor prognosis. Diffuse disease extent and small for gestational age were the most important markers of risk of death in NEC newborns submitted to surgery.

Objetivo: Avaliar a influência da localização da enterocolite necrosante neonatal na mortalidade de recém-nascidos (RN) submetidos à laparotomia exploradora. Métodos: Estudo de coorte prospectiva de 141 recém-nascidos com ECN submetidos consecutivamente à laparotomia exploradora no período de novembro de 1991 a dezembro de 2005. Foram avaliados dados epidemiológicos, localização e extensão da doença, crescimento intra-uterino e o número de óbitos no período de 60 dias após a cirurgia. Resultados: Setenta e quatro (52,5%) crianças eram do sexo masculino, com peso médio de nascimento de 1.589 ± 665 gramas, com idade gestacional média de 33,6 ± 2,9 semanas. Prematuridade ocorreu em 84,4% (119/141) dos RN. Cinqüenta e sete (40,4%) eram pequenos para a idade gestacional. Óbito ocorreu em 68 crianças (48,2%). Na análise bivariada, observou-se que o comprometimento do jejuno-íleo foi associado com alta mortalidade (20 óbitos - 76,9%; OR = 20; intervalo de confiança de 95% = 4,6 - 96,3; p < 0,001) e que a doença no jejuno estava associada à maior extensão da ECN. Entretanto, no modelo de regressão logística múltipla com controle individual de cada variável, a doença no jejuno-íleo (OR = 0,61; intervalo de confiança de 95% = 0,06 - 6,14; p = 0,68) e no intestino grosso (OR = 2,91; intervalo de confiança de 95% = 0,81 - 10,50; p = 0,10) não foram consideradas fatores de risco para o óbito. Conclusões: Em análise adequada, com controle isolado de cada variável estudada, a mortalidade foi independente da localização da ECN no intestino delgado ou no intestino grosso. Porém, a localização da doença no jejuno foi um marcador de maior extensão da ECN e, conseqüentemente, de pior prognóstico. Extensão difusa da doença e recém-nascidos PIG foram os mais importantes fatores de risco de ocorrência de óbito nesses recém-nascidos submetidos à cirurgia. / Aim of the study: To evaluate the effect of disease site on the mortality rate of newborns with necrotizing enterocolitis (NEC) undergoing exploratory laparotomy. Methods: Prospective cohort of 141 consecutive newborns with NEC who underwent laparotomy from November 1991 to December 2005. The study variables included epidemiologic data, disease site and extent, intrauterine growth, and number of deaths in the 60 days after operation. The protocol was approved by the institution’s Research Ethics Committee. Main results: Seventy-four (52.5%) infants were male. Mean birth weight was 1,589 ± 665 g, and mean gestational age was 33.6 ± 2.9 weeks. One-hundred and nineteen (84.4%) newborns were premature. Small for gestational age was observed in 57 (40.4%). Sixty-eight (48.2%) infants died. Bivariate analysis revealed that involvement of the jejunum and ileum was associated with high mortality rates (20 deaths, 76.9%; OR = 20; 95% 95% CI = 4.6 – 96.3; p < 0.001), and that involvement of the jejunum was associated with greater disease extent. After controlling for individual variables, logistic regression showed that the mortality associated with jejunum and ileum involvement (OR = 0.61; 95% CI = 0.06 - 6.14; p = 0.68) did not differ from that associated with large bowel involvement (OR = 2.91; 95% CI = 0.81 – 10.50; p = 0.10); however, jejunum involvement remained significantly associated with disease extent. Conclusions: NEC-related mortality in newborns undergoing laparotomy was not influenced by disease site (small or large bowel). However, jejunum involvement was a marker of greater disease extent and therefore of poor prognosis. Diffuse disease extent and small for gestational age were the most important markers of risk of death in NEC newborns submitted to surgery.

INTRODUÇÃO: O transplante de intestino (TI) estabeleceu-se como tratamento para pacientes com falência intestinal e complicações da nutrição parenteral. Entretanto, sepse continua sendo a principal causa de mortalidade. A lesão causada pela isquemia seguida de reperfusão (LIR) é apontada como um dos fatores de ruptura da barreira mucosa intestinal, com consequente translocação bacteriana e sepse, seja precocemente, por lesão epitelial direta, seja mais tardiamente pela sua associação com o desenvolvimento da rejeição celular aguda. Criou-se um modelo de TI em porcos jovens com a finalidade de estudar a LIR e seus efeitos no epitélio intestinal. MÉTODOS: Para a padronização do modelo, foram realizados 25 procedimentos, tendo sido testados os tamanhos dos animais, as soluções de preservação, o tipo de drenagem venosa, o tipo de reconstrução intestinal e o tempo de duração do experimento. Na pesquisa propriamente dita, 20 porcos jovens foram submetidos a TI ortotópico. Dois grupos foram determinados conforme o tempo de isquemia fria a que foi submetido o intestino: grupo 1 (n=12) 90 minutos (min) e grupo 2 (n=8) 180 min. O procedimento foi realizado sob técnica asséptica e as anastomoses vasculares realizadas entre a aorta do doador e a aorta infra-renal do receptor e a veia porta do doador e a veia cava inferior do receptor. O trânsito intestinal foi reconstruído através de anastomoses entre o jejuno proximal do doador e do receptor e o íleo terminal do doador e do receptor. A solução de preservação utilizada foi Euro Collins. Não foi administrada medicação imunossupressora, exceto pela metilprednisolona (20mg/kg) no momento da reperfusão. Fragmentos de intestino foram obtidos: 1 no momento da laparotomia do doador, o fragmento basal, considerado controle, 2 30 min após a reperfusão e 3 3 dias após o transplante. Os fragmentos assim obtidos foram submetidos a: 1 análise histológica com coloração de hematoxilina-eosina (HE), 2 análise imunoistoquímica para a detecção de infiltração da mucosa por neutrófilos (marcados pelos grânulos ricos em mieloperoxidase MPO), 3 análise histoquímica para quantificação de células epiteliais em apoptose pelo método TUNEL, 4 análise da expressão dos genes da endotelina-1 (ET-1) e da interleucina-6 (IL-6), do gene antiapoptótico Bcl-XL e do gene pró-apoptótico Bak. A análise estatística foi realizada utilizando-se o teste de Mann-Whitney na comparação entre os grupos e, na análise da evolução temporal da LIR em cada grupo, o teste de Friedman seguido do teste post hoc de Dunn quando detectada diferença estatisticamente significante. RESULTADOS: Não foram encontradas diferenças entre os grupos quanto às alterações histológicas estudadas. O grau de infiltração da mucosa por neutrófilos elevou-se significantemente nos dois grupos 30 min após perfusão, tendo persistido elevado 3 dias após o TI somente no grupo 2. O número de células epiteliais em apoptose detectadas pelo método TUNEL sofreu incremento significante apenas no grupo 1, 3 dias após o procedimento. As duas citocinas estudadas, IL-6 e ET-1 mostraram elevação significante 30 minutos após a reperfusão, tendo retornado aos níveis basais 3 dias após a cirurgia em ambos os grupos. Detectou-se redução significante da expressão do Bcl-XL somente no grupo 1, 3 dias após o TI. CONCLUSÕES: As citocinas estudadas estão envolvidas no processo de LIR nas fases iniciais do TI. Ocorre diminuição da expressão de gene anti-apoptótico e aumento do número de células em processo de morte celular de maneira mais intensa no grupo submetido a menor tempo de isquemia / INTRODUCTION: Intestinal transplantation (ITx) has become an accepted mode of treatment of intestinal failure patients who develop parenteral nutrition-related complications. Overall outcomes have dramatically improved but sepsis remains the leading cause of mortality. Ischemia-reperfusion injury (IRI) has been related to the development of sepsis due either to direct mucosal damage or to increased risk of acute cellular rejection. An experimental ITx model has been idealized in order to better characterize IRI-associated mucosal damage. METHOD: 25 procedures involving 75 outbred pigs were necessary to standardize the procedure. Weight of the animals, venous drainage, intestinal transit reconstruction as well as the time period the animals should be maintained alive were evaluated. Orthotopic ITx was performed in 20 hybrid pigs. Two groups were assigned according to cold ischemia time (CI): group 1 (n=12) 90 minutes (min), group 2 (n=8) 180 min. The procedure was performed under aseptic technique and portal drainage was adopted as standard. Intestinal transit reconstruction involved the performance of termino-terminal anastomosis between donor and recipient jejunum and donor and recipient terminal ileum. Euro-Collins was used as preservation solution. 20mg/kg of metilprednisolone was administered at reperfusion and no other immunosuppressive drug has been employed. Specimens were collected from the donor at laparotomy, and from the receptor, 30 min, and 3 days after reperfusion. Mucosal damage was assigned by histological evaluation with hematoxylin-eosin dye. Neutrophilic infiltration was quantified using myeloperoxidase (MPO) immunohistochemical assay and epithelial cell apoptosis was also assigned by means of TUNEL assay. Molecular biology involved the quantification of the expression of the IL-6, ET-1, Bak, and Bcl-XL genes. RESULTS: No statistical difference was detected between the groups as far as plain histological evaluation is regarded. Neutrophilic infiltration increased in a similar fashion in both groups, but lasted longer in group 2. Apoptosis detected by TUNEL showed significant increase in group 1, 3 days after surgery. Anti-apoptotic gene Bcl-XL had its expression decreased in group 1, in 3 days as well. Endothelin-1 and IL-6 genes expression increased 30 min after the procedure and had already returned to baseline 3 d after surgery. CONCLUSION: IL-6 and ET-1 are involved precociously in the development of intestinal IRI. Neutrophilic infiltration lasted longer in the group submitted to longer CI. Although there were no significant differences between the groups, significant increase in the number of apoptotic epithelial cells 3 days after reperfusion could be detected in animals

<p>One of the main obstacles to maintaining patients with short bowel syndrome on parenteral nutrition, or successfully transplanting these patients with a small bowel graft, is the many severe infections that occur. Evidence is accumulating that translocating bacteria from the patient’s bowel causes a significant part of these infections. In this thesis bacterial translocation is studied in a Thiry-Vella loop of defunctionalised small bowel in the rat. </p><p>Bacterial translocation to the mesenteric lymph nodes (MLNs) occurs in almost 100% of the rats after three days. No systemic spread of bacteria is observed unless there is additional immunosupression with depletion of Kupffer cells in the liver. However, blocking the function of α/β T cells does not increase the translocation. Removal of MLNs does not either aggravate bacterial translocation in the Thiry-Vella loop model. Conversely, after small bowel transplantation translocating bacteria spread systemically if the MLNs are removed. </p><p>The Thiry-Vella loop should also be a suitable model for the testing of potentially translocation-inhibiting substances. Reinforcement of the intestinal barrier with glutamine or phosphatidylcholine proved insufficient in decreasing bacterial translocation. Even selective bowel decontamination with tobramycin failed to abolish bacterial translocation. Thus, it seems that the driving force for translocation in this model is strong regardless of the relatively small trauma of intestinal defunctionalisation.</p><p>Flow cytometric studies of the immune cells in the spleen MLNs showed a decrease in MHC class II positive T cells in the MLNs of the Thiry-Vella loop. Concurrently the number of macrophages increased with time as observed by immunohistochemistry. The fraction of MHC class II negative macrophages increased in the spleens of rats treated with glutamine. </p><p>In conclusion, the Thiry-Vella loop model offers possibilities of immunological as well as mechanistic studies on bacterial translocation from small intestine.</p>

One of the main obstacles to maintaining patients with short bowel syndrome on parenteral nutrition, or successfully transplanting these patients with a small bowel graft, is the many severe infections that occur. Evidence is accumulating that translocating bacteria from the patient’s bowel causes a significant part of these infections. In this thesis bacterial translocation is studied in a Thiry-Vella loop of defunctionalised small bowel in the rat. Bacterial translocation to the mesenteric lymph nodes (MLNs) occurs in almost 100% of the rats after three days. No systemic spread of bacteria is observed unless there is additional immunosupression with depletion of Kupffer cells in the liver. However, blocking the function of α/β T cells does not increase the translocation. Removal of MLNs does not either aggravate bacterial translocation in the Thiry-Vella loop model. Conversely, after small bowel transplantation translocating bacteria spread systemically if the MLNs are removed. The Thiry-Vella loop should also be a suitable model for the testing of potentially translocation-inhibiting substances. Reinforcement of the intestinal barrier with glutamine or phosphatidylcholine proved insufficient in decreasing bacterial translocation. Even selective bowel decontamination with tobramycin failed to abolish bacterial translocation. Thus, it seems that the driving force for translocation in this model is strong regardless of the relatively small trauma of intestinal defunctionalisation. Flow cytometric studies of the immune cells in the spleen MLNs showed a decrease in MHC class II positive T cells in the MLNs of the Thiry-Vella loop. Concurrently the number of macrophages increased with time as observed by immunohistochemistry. The fraction of MHC class II negative macrophages increased in the spleens of rats treated with glutamine. In conclusion, the Thiry-Vella loop model offers possibilities of immunological as well as mechanistic studies on bacterial translocation from small intestine.

INTRODUÇÃO: O transplante de intestino (TI) estabeleceu-se como tratamento para pacientes com falência intestinal e complicações da nutrição parenteral. Entretanto, sepse continua sendo a principal causa de mortalidade. A lesão causada pela isquemia seguida de reperfusão (LIR) é apontada como um dos fatores de ruptura da barreira mucosa intestinal, com consequente translocação bacteriana e sepse, seja precocemente, por lesão epitelial direta, seja mais tardiamente pela sua associação com o desenvolvimento da rejeição celular aguda. Criou-se um modelo de TI em porcos jovens com a finalidade de estudar a LIR e seus efeitos no epitélio intestinal. MÉTODOS: Para a padronização do modelo, foram realizados 25 procedimentos, tendo sido testados os tamanhos dos animais, as soluções de preservação, o tipo de drenagem venosa, o tipo de reconstrução intestinal e o tempo de duração do experimento. Na pesquisa propriamente dita, 20 porcos jovens foram submetidos a TI ortotópico. Dois grupos foram determinados conforme o tempo de isquemia fria a que foi submetido o intestino: grupo 1 (n=12) 90 minutos (min) e grupo 2 (n=8) 180 min. O procedimento foi realizado sob técnica asséptica e as anastomoses vasculares realizadas entre a aorta do doador e a aorta infra-renal do receptor e a veia porta do doador e a veia cava inferior do receptor. O trânsito intestinal foi reconstruído através de anastomoses entre o jejuno proximal do doador e do receptor e o íleo terminal do doador e do receptor. A solução de preservação utilizada foi Euro Collins. Não foi administrada medicação imunossupressora, exceto pela metilprednisolona (20mg/kg) no momento da reperfusão. Fragmentos de intestino foram obtidos: 1 no momento da laparotomia do doador, o fragmento basal, considerado controle, 2 30 min após a reperfusão e 3 3 dias após o transplante. Os fragmentos assim obtidos foram submetidos a: 1 análise histológica com coloração de hematoxilina-eosina (HE), 2 análise imunoistoquímica para a detecção de infiltração da mucosa por neutrófilos (marcados pelos grânulos ricos em mieloperoxidase MPO), 3 análise histoquímica para quantificação de células epiteliais em apoptose pelo método TUNEL, 4 análise da expressão dos genes da endotelina-1 (ET-1) e da interleucina-6 (IL-6), do gene antiapoptótico Bcl-XL e do gene pró-apoptótico Bak. A análise estatística foi realizada utilizando-se o teste de Mann-Whitney na comparação entre os grupos e, na análise da evolução temporal da LIR em cada grupo, o teste de Friedman seguido do teste post hoc de Dunn quando detectada diferença estatisticamente significante. RESULTADOS: Não foram encontradas diferenças entre os grupos quanto às alterações histológicas estudadas. O grau de infiltração da mucosa por neutrófilos elevou-se significantemente nos dois grupos 30 min após perfusão, tendo persistido elevado 3 dias após o TI somente no grupo 2. O número de células epiteliais em apoptose detectadas pelo método TUNEL sofreu incremento significante apenas no grupo 1, 3 dias após o procedimento. As duas citocinas estudadas, IL-6 e ET-1 mostraram elevação significante 30 minutos após a reperfusão, tendo retornado aos níveis basais 3 dias após a cirurgia em ambos os grupos. Detectou-se redução significante da expressão do Bcl-XL somente no grupo 1, 3 dias após o TI. CONCLUSÕES: As citocinas estudadas estão envolvidas no processo de LIR nas fases iniciais do TI. Ocorre diminuição da expressão de gene anti-apoptótico e aumento do número de células em processo de morte celular de maneira mais intensa no grupo submetido a menor tempo de isquemia / INTRODUCTION: Intestinal transplantation (ITx) has become an accepted mode of treatment of intestinal failure patients who develop parenteral nutrition-related complications. Overall outcomes have dramatically improved but sepsis remains the leading cause of mortality. Ischemia-reperfusion injury (IRI) has been related to the development of sepsis due either to direct mucosal damage or to increased risk of acute cellular rejection. An experimental ITx model has been idealized in order to better characterize IRI-associated mucosal damage. METHOD: 25 procedures involving 75 outbred pigs were necessary to standardize the procedure. Weight of the animals, venous drainage, intestinal transit reconstruction as well as the time period the animals should be maintained alive were evaluated. Orthotopic ITx was performed in 20 hybrid pigs. Two groups were assigned according to cold ischemia time (CI): group 1 (n=12) 90 minutes (min), group 2 (n=8) 180 min. The procedure was performed under aseptic technique and portal drainage was adopted as standard. Intestinal transit reconstruction involved the performance of termino-terminal anastomosis between donor and recipient jejunum and donor and recipient terminal ileum. Euro-Collins was used as preservation solution. 20mg/kg of metilprednisolone was administered at reperfusion and no other immunosuppressive drug has been employed. Specimens were collected from the donor at laparotomy, and from the receptor, 30 min, and 3 days after reperfusion. Mucosal damage was assigned by histological evaluation with hematoxylin-eosin dye. Neutrophilic infiltration was quantified using myeloperoxidase (MPO) immunohistochemical assay and epithelial cell apoptosis was also assigned by means of TUNEL assay. Molecular biology involved the quantification of the expression of the IL-6, ET-1, Bak, and Bcl-XL genes. RESULTS: No statistical difference was detected between the groups as far as plain histological evaluation is regarded. Neutrophilic infiltration increased in a similar fashion in both groups, but lasted longer in group 2. Apoptosis detected by TUNEL showed significant increase in group 1, 3 days after surgery. Anti-apoptotic gene Bcl-XL had its expression decreased in group 1, in 3 days as well. Endothelin-1 and IL-6 genes expression increased 30 min after the procedure and had already returned to baseline 3 d after surgery. CONCLUSION: IL-6 and ET-1 are involved precociously in the development of intestinal IRI. Neutrophilic infiltration lasted longer in the group submitted to longer CI. Although there were no significant differences between the groups, significant increase in the number of apoptotic epithelial cells 3 days after reperfusion could be detected in animals