Therapeutic effectiveness of percutaneous drainage and factors for performing an interval appendectomy in pediatric appendiceal abscess

Background: In this study, we studied the therapeutic effectiveness of percutaneous drainage with antibiotics and the need for an interval appendectomy for treating appendiceal abscess in children with a research-oriented dataset released by the Bureau of National Health Insurance in Taiwan through the Collaboration Center for Health Information Application (CCHIA). Methods: We identified 1225 patients under 18 years of age who had non-surgical treatment for an appendiceal abscess between 2007 and 2012 in a Taiwan CCHIA dataset. The treatment included percutaneous drainage with antibiotics or antibiotics alone. We also analyzed data of patient's baseline characteristics, outcomes of percutaneous drainage, and indicating factors for performing an interval appendectomy. Results: Totally, 6190 children had an appendiceal abscess, an 1225 patients received non-operative treatment. Of 1225 patients, 150 patients received treatment with percutaneous drainage and antibiotics, 78 had recurrent appendicitis, 185 went on to receive an interval appendectomy, and 10 had postoperative complications after the interval appendectomy. We found that patients treated with percutaneous drainage and antibiotics had a significantly lower rate of recurrent appendicitis (p < 0.05), a significantly smaller chance of receiving an interval appendectomy (p < 0.05), and significantly fewer postoperative complications after the interval appendectomy (p < 0.05) than those without percutaneous drainage treatment. Older children (13 ~ 18 years) patients were found to have a significantly smaller need to receive an interval appendectomy than those who were ≤ 6 years of age (odd ratio (OR) = 2.071, 95 % confidence interval (CI) = 1.34-3.19, p < 0.01), and those who were 7 ~ 12 years old (OR = 1.662, 95 % CI = 1.15-2.41, p < 0.01). In addition, those treated with percutaneous drainage were significantly less indicated to receive an interval appendectomy later (OR = 2.249, 95 % CI = 1.19 ~ 4.26, p < 0.05). In addition, those with recurrent appendicitis had a significantly increased incidence of receiving an interval appendectomy later (OR = 3.231, 95 % CI = 1.95 ~ 5.35, p < 0.001). Conclusions: In this study, we used nationwide data to demonstrate therapeutic effectiveness of percutaneous drainage and antibiotics was more beneficial than only antibiotics in treating patients with an appendiceal abscess. We also found three factors that were significantly associated with receiving an interval appendectomy: recurrent appendicitis, being aged ≤ 13 years, and treatment with antibiotics only.