The effects of irrigation on outcomes in cases of perforated appendicitis in children

Abstract

Introduction

Appendicitis is the most common indication for urgent abdominal operation in children. Approximately 20%–30% of patients will have a perforation at operation. Intra-abdominal abscess after appendectomy is reported in 3%–20% of patients and adds significantly to hospital stay with increased morbidity and overall cost. Surgical dogma has long advocated for irrigation in the setting of gross pus to prevent abscess formation.

Methods

Following IRB approval, data were retrospectively collected for children who had undergone appendectomy for perforated appendicitis at one of two children's hospitals over the course of 5 y. Perforation was determined by review of operative notes. All patients had free fluid in their peritoneal cavity evacuated by suction, whereas some of the patients also had their peritoneal cavity irrigated with normal saline. Postoperative intra-abdominal abscess rates were determined based on clinical symptoms and confirmatory radiologic studies.

Results

There were 99 patients in the suction-only group and 139 in the irrigation group. Standard demographics were relatively similar between the two groups. There were significantly lower rates of intra-abdominal abscess formation (4.0% versus 17.2%, P = 0.002) and wound infection (1.0% versus 8.6%, P = 0.003) in the suction-only group compared with the irrigation group. We further analyzed abscess rates by surgical treatment, either laparoscopic or open appendectomy. There were 85 patients in the laparoscopic group and 152 patients in the open appendectomy group. In this subgroup analysis, there were also significantly lower rates of abscess formation in patients treated with suction only compared with irrigation in the laparoscopic (3.5% versus 18.8%, P = 0.012) and open appendectomy groups (4.2% versus 16.3%, P = 0.036).

Conclusions

Results of this retrospective review indicate that a suction-only approach significantly decreased rates of abscess formation and wound infections compared to irrigation in cases of perforated appendicitis in children.

Introduction

Appendicitis is the most common indication for urgent operation in children, with approximately 80,000 cases per year in the United States. At the time of operation, 20%–30% of patients will have a perforation [1]. Of patients with perforated appendicitis, 3%–20% of patients will develop an intra-abdominal abscess. The presence of an intra-abdominal abscess often necessitates a second procedure for drainage and frequently requires an additional general anesthetic for young children. A retrospective review of patients with perforated appendicitis determined that the formation of a postoperative intra-abdominal abscess added an average of 1 wk of inpatient hospital stay and roughly doubled the hospital costs compared to uncomplicated perforated appendicitis [2].

The use of irrigation was based on studies that demonstrated that the higher the dose of inoculum of bacteria in a wound, the increased chance and severity of infection. Based on this premise, the hypothesis was that if the bacterial load is diluted, the patient will have less risk of peritonitis or a less severe course. To date, no studies have described the effects of irrigation on the inflammatory cells and other defenses in the peritoneal cavity.

Surgical dogma and literature throughout the past 50 y has long advocated for intra-abdominal irrigation to prevent abscess formation and surgical site infections [3]. Historically, antibiotic irrigation was advocated, though this practice is currently uncommonly used because of a lack of clinical evidence demonstrating efficacy [4]. Many current protocols for the treatment of acute appendicitis advocate for intra-abdominal irrigation with a normal saline solution [3], [5], [6]. Critical review of these protocols reveals that many of them were developed in an era where open appendectomy was the standard of care and that a majority of the stipulations related to irrigation were based on best practice rather than evidence-based postulates. While comparison of open to laparoscopic appendectomy demonstrates no difference in abscess formation or wound infection [7], more recent studies in adult patients indicate that irrigation during appendectomy may increase the incidence of abscess formation [8], [9]. This is hypothesized to be due to spread of bacteria and intestinal content throughout the abdomen with irrigation, predisposing to abscess formation.

Current practice in pediatric surgery appears to be dichotomous, with many surgeons strongly advocating for irrigation and many advocating against. There have been no studies dedicated to the effects of irrigation on abscess formation and wound infections in perforated appendicitis in children. We sought to determine whether irrigation of the peritoneal cavity in children with perforated appendicitis affected the rates of intra-abdominal abscess formation as well as surgical site infections.