Use of free blood in the stomach to diagnose gastric mucosal lesions prior to endoscopy: the Sanguis-filum

Abstract Diagnosis of upper gastrointestinal (UGI) mucosal lesions primarily uses endoscopy. Based on our preliminary work in Zambia which showed that free blood in the stomach was associated with gastric mucosal lesions, we designed a bedside tool, the Sanguis-filum (S-filum). In this study, we investigated the diagnostic accuracy of the S-filum for detecting UGI mucosal lesions. We tested the technique on 200 consenting patients, 112 (56%) females and 88 (44%) males attending for endoscopy in the University Teaching Hospital, Lusaka. Ninety-five (47%) of the patients had visible mucosal lesions; 45 (23%) of them had peptic ulceration and 9 (5%) had gastric cancer. Ninety-one (46%) of S-filum tests were positive.We found an association between positive S-filum results and presence of mucosal lesions (OR 2.2; 95% CI 1.2–4.1, p = 0.007) but not gastric cancer (OR 3.5; 95% CI 0.7–22, p = 0.09). S-filum was insufficiently sensitive, missing mucosal lesions in 54%, and gastric cancer in 33% of cases. Sensitivity was 56%, specificity 64% and the area under the receiver operating characteristic (ROC) curve was 0.60. For GC, the sensitivity was 67%, specificity 64% and area under the ROC 0.65. As a screening test prior to a definitive test must be highly sensitive, the S-filum is not sufficiently accurate for use as a diagnostic tool for UGI mucosal lesions.