Saline vs Tissue Plasminogen Activator Irrigations after Drain Placement for Appendicitis-Associated Abscess: A Prospective Randomized Trial.

Background: Emerging data suggest instillation of tissue plasminogen activator (tPA) is safe and potentially efficacious in the treatment of intra-abdominal abscess. To date, prospective comparative data are lacking in children. Therefore, we conducted a randomized trial comparing abscess irrigation with tPA and irrigation with saline alone.

Study Design: After IRB approval, children with an abscess secondary to perforated appendicitis who had a percutaneous drain placed for treatment were randomized to twice-daily instillation of 13 mL 10% tPA or 13 mL normal saline. All patients were treated with once-daily dosing of ceftriaxone and metronidazole throughout their course. The primary end point variable was duration of hospitalization after drain placement. Using a power of 0.8 and an α of 0.05, a sample size of 62 patients was calculated.

Results: Sixty-two patients were enrolled between January 2009 and February 2013. There were no differences in demographics, abscess size, abscess number, admission WBC, or duration of symptoms. Duration of hospitalization after drainage was considerably longer with the use of tPA. There was no difference in total duration of hospitalization, days of drainage, or days of antibiotics. However, medication charges were higher with tPA.

Conclusions: There are no advantages to routine tPA flushes in the treatment of abdominal abscess secondary to perforated appendicitis in children.