Abdominal drainage following appendectomy and cholecystectomy.

Consecutive patients undergoing emergency appendectomy (283) or urgent cholecystectomy (51) were prospectively studied for the development of post-operative incisional or peritoneal sepsis. Severity of the original peritoneal infection was carefully recorded, while use of a Penrose dam to drain the peritoneum was randomized according to pre-assigned hospital number. Both aerobic and anaerobic cultures were taken from the abdomen at the time of operation as well as from all postoperative infectious foci. Results demonstrated no essential differences in incidence of wound and peritoneal infection following appendectomy for simple or suppurative appendicitis (187) or following cholecystectomy for acute cholecystitis (51). However, with gangrenous or perforative appendicitis (94), incisional and intra-abdominal infection rates were 43% and 45%, respectively, when a drain was used; yet only 29 and 13%, respectively, without a drain. These latter differences were significant (p < 0.001). In addition, intra-abdominal abscesses were three times as likely to drain through the incision than along any tract provided by the rubber conduit. Cultures revealed that hospital pathogens accounted for a greater proportion of wound and peritoneal sepsis after cholecystectomy and appendectomy for simple or suppurative appendicitis if a drain had been inserted than if managed otherwise. By contrast, a mixed bacterial flora was responsible for most infections following appendectomy for gangrenous or perforated appendicitis, irrespective as to use of a drain.