Comparison of Appendectomy for Perforated Appendicitis With and Without Abscess: A National Surgical Quality Improvement Program Analysis

Background: Outcomes of appendectomy stratified by type of complicated appendicitis (CA) features are poorly researched, and the evidence to guide operative versus nonoperative management for CA is lacking. This study aimed to determine laparoscopic-to-open conversion risk, postoperative abscess risk, unplanned readmission risk, and length of hospital stay (LOS) associated with appendectomy in patients with perforated appendicitis without abscess (PA) and perforated appendicitis with abscess (PAWA) compared with a control cohort of nonperforated appendicitis (NPA).

Methods: The 2016-2017 National Surgical Quality Improvement Program Appendectomy-targeted database identified 12,537 (76.1%) patients with NPA, 2142 (13.0%) patients with PA, and 1799 (10.9%) patients with PAWA. Chi-squared analysis and analysis of variance were used to compare categorical and continuous variables. Binary logistic and linear regression models were used to compare risk-adjusted outcomes.

Results: Compared with NPA, PA and PAWA had higher rates of conversion (0.8% versus 4.9% and 6.5%, respectively; P < 0.001), postoperative abscess requiring intervention (0.6% versus 4.8% and 7.0%, respectively; P < 0.001), readmission (2.8% versus 7.7% and 7.6%, respectively; P < 0.001), and longer median LOS (1 day versus 2 days and 2 days, respectively; P < 0.001). PA and PAWA were associated with increased odds of postoperative abscess (odds ratio [OR]: 7.18, 95% confidence interval [CI]: 5.2-9.8 and OR: 9.94, 95% CI: 7.3-13.5, respectively), readmission (OR: 2.70, 95% CI: 2.1-3.3 and OR: 2.66, 95% CI: 2.2-3.3, respectively), and conversion (OR: 5.51, 95% CI: 4.0-7.5 and OR: 7.43, 95% CI: 5.5-10.1, respectively). PA was associated with an increased LOS of 1.7 days and PAWA with 1.9 days of LOS (95% CI: 1.5-1.8 and 1.7-2.1, respectively).

Conclusions: Individual features of CA were independently associated with outcomes. Further research is needed to determine if surgical management is superior to nonoperative management for CA.