BOSTON – Operative approach, as previously suggested, was not a significant predictor of postappendectomy organ space infection in children, according to a large, national database analysis.
Instead, organ space infection appears to be associated with largely nonmodifiable factors of disease severity, preoperative sepsis, and long operative duration, Dr. Fergal J. Fleming said at the annual meeting of the American Surgical Association.
"It would appear that the die is cast with respect to the risk of organ space infection at the time of presentation," he said. "This would suggest that our focus, in terms of quality improvement, should be on identifying patients at highest risk for complications."
The study findings are important because laparoscopic appendectomy has become widely accepted in children and adults, but has also been associated with increased odds of intra-abdominal abscess formation in adults (Ann. Surg. 2010;252:895-900), said Dr. Fleming, a colorectal surgeon at the University of Rochester (N.Y.) Medical Center.
To determine the effect of surgical approach on organ space infection (OSI) in children, Dr. Fleming and his associates analyzed 5,097 children, aged 2-18 years, undergoing open or laparoscopic appendectomy for acute appendicitis in the 2012 ACS National Surgical Quality Improvement Program (ACS NSQIP) pediatric database. The approach was laparoscopic in 4,514 patients (88.5%) and open in 583 patients.
OSI occurred in only 155 children (3%), but accounted for more than half of reoperations and nearly two-thirds of readmissions at 30 days, Dr. Fleming reported.
The unadjusted OSI rate was 0.9% (31/3,613) for uncomplicated appendicitis and 8.4% (124/1,484) for complicated appendicitis, which was a significant difference (P less than .001).
OSI rates did not differ significantly between laparoscopic and open surgery for uncomplicated appendicitis (0.8% vs. 1.7%; P = .160) and complicated appendicitis (8.7% vs. 7.3%; P = .415), defined by abscess, perforation, or sepsis.
In multivariable logistic regression analysis, complicated appendicitis was again the major factor associated with OSI (adjusted odds ratio, 4.85), he said. Other significant drivers were wound class III/IV (OR, 4.17), preoperative sepsis (OR, 2.19), and operative time of 60 minutes or more (OR, 2.15).
The model, which controlled for age, sex, pulmonary comorbidity, obesity, and emergency operations, had excellent predictive ability, with a c-statistic of 0.837, Dr. Fleming said.
He acknowledged that baseline differences between the two groups suggested that sicker children may have been selected as candidates for open surgery. Compared with the laparoscopic group, the open surgery group had significantly higher rates of preoperative sepsis/septic shock (24.7% vs. 14.7%), complicated appendicitis (58.8% vs. 25.3%), and emergency surgery (74.4% vs. 62%; all P values less than .001).
"Now that your group has identified these perioperative risk factors for children undergoing emergency appendectomy, do you have any guidelines for pediatric surgeons on how to follow their patients postop to identify organ space infections earlier?" asked discussant Dr. Paul Colombani, Children’s Surgeon-in Charge, Johns Hopkins Hospital, Baltimore.
Dr. Fleming suggested a bundle for high-risk patients that could include predischarge education for parents and patients, an early clinic visit before postoperative day 9, and a structured telephone call on day 2 or 3 post discharge to run through risk factors such as low-grade fever, malaise, and diarrhea. He noted that high-risk patients represented less than 15% of the cohort, but 80% of OSI events.
Dr. Fleming reported having no financial disclosures.
The complete manuscript of this study and its presentation at the American Surgical Association’s 134th Annual Meeting, April 2014, in Boston, is anticipated to be published in Annals of Surgery, pending editorial review.