Renal excretion of ingested gastrografin: clinical relevance in early postoperative treatment of patients who have undergone gastric surgery

OBJECTIVE: We performed this study to evaluate the clinical relevance of renal excretion of ingested Gastrografin (methylglucamine diatrizoate) revealed on CT in the early treatment of patients who have undergone gastric surgery. SUBJECTS AND METHODS: Unenhanced abdominal CT was performed before and then 1 hr to 1 hr 30 min after Gastrografin ingestion in 30 patients 7 days after gastric surgery and in 19 healthy adults who served as the control group. CT scans were reviewed for the opacification of the renal collecting system or urinary bladder after Gastrografin ingestion, a finding that represents renal excretion of the ingested contrast medium. RESULTS: In the control group, four (21 %) of the 19 healthy adults showed renal excretion of ingested Gastrografin visualized as opacification of the urinary tract on CT scans obtained 1 hr to 1 hr 30 min after ingestion of the substance. Renal excretion of the ingested Gastrografin was seen in 19 (63%) of the 30 patients, a significantly larger percentage than in the control group (z score, p < 0.01). No patient showed either radiologic or clinical evidence of leakage from the anastomotic site. CONCLUSION: Renal excretion of ingested Gastrografin is frequently visualized on CT in patients without anastomotic leakage during the early postoperative period after gastric surgery, and this phenomenon is not rare, even in healthy adults. Therefore, renal excretion seen on CT should not be regarded as a sign of anastomotic leakage in early postoperative patients.