Irrigation No Better Than Suction for Perforated Appendicitis

By Christina Frangou
 
Peritoneal irrigation offers no advantage over suction alone during laparoscopic surgery in children with perforated appendicitis, according to a prospective, randomized trial presented at the 132ndannual meeting of the American Surgical Association (abstract 19).

In a trial involving 220 children, researchers found outcomes were unchanged when surgeons performed peritoneal irrigation for perforated appendicitis rather than suction alone. The study showed similar rates of abscess, location of abscesses, hospital length of stay (LOS), narcotic doses and hospital charges when children had peritoneal irrigation or suction alone.

“I would say this study is definitive, after 110 observations in each group and absolutely no differences between groups in outcomes, that a moderate volume of saline irrigation does not affect outcome during laparoscopic appendectomy for perforated appendicitis in children,” said Shawn D. St. Peter, MD, director of the Center for Prospective Clinical Trials and a pediatric surgeon at Children’s Mercy Hospital, Kansas City, Mo. The results, however, cannot be extrapolated to other contaminated cases, he cautioned.

The debate over irrigation of the peritoneal cavity has gone on for more than a century, with the first reports of irrigation dating back to 1906. However, robust studies in patients with perforated appendicitis are few and all previous studies were conducted in the pre-laparoscopic era. Anecdotal reports suggest surgeons are split over whether to irrigate for a perforated appendix.

Dr. St. Peter and his colleagues designed a prospective, randomized trial to compare the effects of irrigation with those of suction alone during laparoscopic appendectomy in children with perforated appendicitis. Perforation was defined as stool in the abdomen or a hole in the appendix.

Researchers randomized 220 patients, 110 in each arm, to undergo irrigation with a 1-L bag of normal saline attached to the suction irrigator or to suction alone. The two groups were well matched with a mean age of 10 years, weight of 41 kg and body mass index in the 60th to 65th percentile. Both groups had symptoms and temperature of 37.8°C for three days prior to surgery.

All patients underwent a standard three-port appendectomy, followed by placement of a Foley catheter and once-daily dosing of IV ceftriaxone (50 mg/kg) and metronidazole (30 mg/kg) with the regimen outlined in a previous trial on antibiotics from the same investigators. Standard patient-controlled analgesia was used for pain control postoperatively.

Patients had similar outcomes, regardless of whether they had peritoneal irrigation. Eighteen percent of irrigated patients developed abscesses compared with 19% of nonirrigated patients. Irrigation did not affect the location of the abscesses, the number of drains placed, days of drainage, the hospital LOS, the return to regular diet or ultimate cost. Both groups of patients returned to regular diet in 3.5 days, and remained in the hospital 5.5 days. The hospital charges were the same, at around $48,100, for both groups of patients.

One child who was randomized to suction alone underwent irrigation instead due to surgeon preference.

Three patients who underwent suction alone developed postoperative bowel obstruction compared with one in the irrigation group. The difference was not significant, investigators said.

The only difference that approached significance was operative time (P=0.056); however, irrigation prolonged surgery by only four minutes (38.7 vs. 42.8 minutes).

The study stands out for its randomized, prospective format—the latest in a long series that the team from Kansas City has completed, said Michael G. Sarr, MD, James C. Mason professor of surgery at Mayo Clinic, Rochester, Minn.

Dr. Sarr cautioned, however, that the rigid design of the study limits some of the conclusions. The surgeons used a minimum 500 cc to irrigate and had a mean volume of irrigation of 867±327 cc. More volume and an irrigation that contained antibiotics may have had greater influence, he said. Also, irrigation was localized to the area around the appendix.

“This shows definitively that irrigation of less than 1 L in the area around the appendix makes no difference. However, because abscesses also occurred in other distant areas of the abdomen, we don’t know whether intense irrigation throughout the peritoneal cavity would have prevented these abscesses,” said Dr. Sarr.