Extraperitoneal gas following nephrectomy: patterns and duration.

The amount and duration of extraperitoneal gas in normal patients after major renal operations have not been documented. This air may be difficult to separate from that owing to abdominal abscess and, therefore, can be a potential source of diagnostic error in the febrile postoperative patient. A prospective study was performed on 41 postoperative patients to determine the incidence, duration and pattern of extraperitoneal gas in patients undergoing renal operations. No patient had an abscess. Of the abdominal films obtained between 1 and 4 days postoperatively 92 per cent demonstrated gas, 71 per cent were positive between 5 and 8 days and 61 per cent were positive between 9 and 12 days postoperatively. Over-all, 34 of 41 patients had extraperitoneal gas demonstrated on the postoperative abdominal radiographs. Linear and bubbly patterns were demonstrated and, in many cases, the appearance was indistinguishable from that of an abscess. It is important that the benign nature of this postoperative gas be appreciated and not mistaken for an abdominal abscess.