Gastrobronchial fistula is a rare condition as a complication following bariatric surgery. The management of this condition requires the active participation of a pulmonologist, who should be familiar with aspects of the main types of bariatric surgery. Herein, we report the cases of two patients who presented recurrent subphrenic and lung abscess secondary to fistula at the angle of His for an average of 19.5 months. After relaparotomy was unsuccessful, cure was achieved by antibiotic therapy and, more importantly, by stenostomy and endoscopic dilatation, together with the use of clips and fibrin glue in the fistula. These pulmonary complications should not be treated in isolation without a gastrointestinal evaluation since this can result in worsening of the respiratory condition, thus making anesthetic management difficult during endoscopic procedures.

Keywords: Fistula; Lung abscess; Subphrenic abscess; Obesity, surgery; Endoscopy.

Objective: To determine the levels of the tumor markers carcinoembryonic antigen (CEA), cytokeratin 19 fragment (CYFRA21-1) and carbohydrate antigen 15-3 (CA 15-3) in the blood and pleural fluid of patients with benign or malignant pleural effusion, evaluating the sensitivity of each marker in these fluids. Methods: We prospectively evaluated 85 patients with pleural effusion. The study of the pleural fluid observed the criteria established in the literature. Levels of the markers were determined using electrochemiluminescence. The sensitivity was determined on the condition that the specificity was ≥ 90%. Results: Of the 85 cases, 36 (42.4%) were malignant, 30 (35.3%) were benign, and the results were inconclusive in 19 (22.3%). In the malignant cases, the CEA and CYFRA21-1 levels were higher in the pleural fluid than in the blood, which was not observed for CA 15-3. In the benign cases, the CYFRA21-1 levels were higher in the pleural fluid than in the blood, whereas the opposite was found for CEA and CA 15-3. There were significant differences between malignant and benign cases for all markers, in pleural fluid and blood. In the pleural fluid, the sensitivity of CEA, CYFRA21-1 and CA 15-3 was 69.4, 69.4 and 66.7%, respectively, and the combined sensitivity was 80.6%. In the blood, the sensitivity was 57.1%, 71.4% and 48.6% for CEA, CYFRA21-1 and CA 15-3, respectively, and the combined sensitivity was 77%. Conclusion: The results suggest that these markers might be useful in the differentiation between malignant and benign pleural effusion.

Keywords: Biological tumor marker; Cyfra 21.1; CEA; CA 15.3; Pleural effusion.